Incredible plants: Stenogramma

In some respects, red seaweeds (Phylum Rhodophyta) are the most interesting of the three major groups of marine algae inhabiting coastal shorelines. They are the most diverse seaweed group in temperate regions like the western US, they have fascinatingly complex life histories (that topic alone warrants its own post some day), and they occur in a tremendous diversity of growth forms and colors. They can be pink, brown, cherry red, or even greenish!

Generally red seaweeds are smaller and less ostentatious than the large brown seaweeds like kelps that sometimes dominate the intertidal shores of rocky temperate coastlines. But look under mats of surfgrass or in rocky crevices that are seemingly a little too dark for plant life – here you are likely to some of the more intriguing smaller red seaweeds. I came across one such species, Stenogramma californicum, in relative abundance during my exploration of Pfieffer Beach in Big Sur last month. This species has long been one of my favorite reds.

Stenogramma californicum underwater at Pfeiffer Beach, Big Sur, CA, Feb 2018.

The first thing to note about Stenogramma is that is has dichotomous branching. This means that each axis of the plant splits in two at a branching point, with each branch of equal length. Many red seaweeds have dichotomous branches, but Stenogramma has one other feature that makes it almost immediately jump out as distinct from other similar-looking species: in some plants it has thin white longitudinal lines that run down the center of each branch. These lines are actually present on female plants and are the locations where spores (carpospores to be precise) are produced after female eggs are fertilized. There are several orders of branching.

Stenogramma californicum is typically 6 to 20 cm in length. The flat dichotomous branches are up to 1 cm wide and have broadly rounded tips. According to Abbott and Hollenberg (1976) it is a relatively common plant in the northeast Pacific, occurring from British Columbia to Baja California. Related species also occur in British Columbia, Europe, South America, and Australia. In my experience it is not all that frequent along the NE Pacific coast, but there may be some good reasons I have overlooked it in the past: it is a smaller plant, it grows in the low intertidal to subtidal where it may be more challenging to find, and one can easily overlook species one is not specifically hunting for.

Herbarium specimens of Stenogramma in the UC Berkeley University Herbarium.
Left: a female plant, bar = 2 cm long. Right: a tetrasporophyte from Jalama Beach, Santa Barbara
County, CA, bar = 5 mm long.

On the north shore of Pfieffer Beach where I explored last month, it grew in the low intertidal, with or without the cover of surfgrass. The female plants were relatively common. I suspect there are many unanswered questions about the natural history of Stenogramma and smaller seaweed species like it. How long do plants typically live? Which herbivores graze on them? Does Stenogramma produce anti-herbivore compounds? How far do spores travel? How quickly do newly settled spores grow on a rocky substrate? What is the ideal amount of light? How much gene flow occurs between populations that may be separated by kilometers? 

Another plant underwater with articulated coralline algae at Pfeiffer Beach, Feb. 2018.

For smaller species like Stenogramma that may not have immediate economic value, or which don’t play major structural roles in coastal ecosystems (e.g., kelps), it may be hard to find the funding to study many questions about their natural history and ecology. Yet these smaller species, like all others, hold tremendous natural history value. They are each literally a wealth of millions of years of evolutionary innovation, holding some stories that will be forever lost to time, and revealing other stories that will enrich those who seek to know them better.

References

Abbott IA, Hollenberg GJ. 1976. Marine Algae of California. Stanford University Press, Stanford, CA.

Gabrielson PW, Lindstrom SC, O’Kelly CJ. 2012. Keys to the seaweeds and seagrasses of southeast Alaska, British Columbia, Washington, and Oregon. Phycological Contribution Number 8.

Incredible plants: giant sequoia

General Grant tree in the Grant Grove, Kings
Canyon National Park, 2014.

California is a land of superlatives, and especially so botanically. Trees are at the top of the list for California’s record breaking plants: the state is home to the world’s oldest trees (the bristlecone pines, Pinus longaeva), the world’s tallest trees (coast redwood, Sequoia sempervirens), and the world’s largest trees by volume (the giant sequoia, Sequoiadendron giganteum). Each of these record-setting trees occurs in different geographic areas and environments among California’s diverse set of geologies and climates. They are all conifers, a widespread group of gymnosperms (gymnosperms are seed-bearing, but flowerless, vascular plants).

The giant sequoia has a narrow geographic range, found solely on the western slopes of the Sierra Nevada range in central California. It occurs across a fairly broad range of elevations (825-2700 m), though most populations of the species lie between about 1800 and 2100 m above sea-level (Yu et al. 2017). Upper and lower elevations of the species may be limited by low temperatures and low precipitation respectively. The coast redwood is distributed in the coast ranges from central California to southwest Oregon. It typically grows at much lower elevations than the giant sequoia and generally in close proximity to the coast with its cool and foggy maritime air.

The coast redwood is believed to be the closet living relative of the giant sequoia. Both species are classified in the conifer family Cupressaceae which includes cedars, junipers, and cypresses. Metasequoia glyptostroboides (the dawn redwood), which occurs in China and was only discovered within the last century, is a cousin to the two California redwood species. Fossil evidence suggests that redwood-like trees were formerly much more widespread in distribution across the Northern hemisphere. Sequoiadendron for example, may have been distributed in the past in North America, Europe, and New Zealand. Thus, these three redwood species might be considered relict species with greatly constricted modern distributions relative to the past. Perhaps glacial cycles (increased northern latitude ice cover implicated in the case of Metasequoia) and other factors over time have led to the range constriction of this group of conifers.

Hypothesized evolutionary relationships among giant sequoia (Sequoiadendron giganteum), coast redwoods (Sequoia sempervirens), the dawn redwood (Metasequoia glyptostroboides) and other Cupressaceae. Tree after Kusumi et al. 2000. 

The giant sequoia is a behemoth, estimated to be greater in volume than any other tree species in the world. The largest individuals have an imposing presence in the mixed conifer forests in which they occur. The base of the trunk in the largest individuals can often reach up to 11 m in diameter and 90 m in height (a little shorter than the coast redwood). The giant sequoia has reddish fibrous bark like the coast redwood, with deep furrows evident in older, larger trees. Old growth individuals may live several millennia.

Needles and cones in the giant sequoia and coast redwood are different enough to enable easy identification (in addition to differences in native range between the species). The giant sequoia has short pointed leaves that emerge from stems in a radial fashion, whereas most leaves on the coast redwood are pinnate sprays of leaves flattened in one plane. (An interesting exception is the leaves at the very top of a coast redwood which look quite similar to giant sequoia leaves in overall form.) Giant sequoia trees have both male and female cones on the same individual. Female (seed-bearing) cones of Sequoiadendron and Sequoia are both egg shaped and similar in morphology, but cones of the giant sequoia are about twice as large, almost the size of a chicken egg. Female cones of the giant sequoia are produced in clusters high in the foliage and bear small papery seeds a few centimeters in size.

Foliage of giant sequoia (left) and coast redwood (right). Photos from Bearskin Grove, Sequoia National Forest (2014) and Ventana Wilderness, Los Padres National Forest, Big Sur (2015).

Female cones and seedling of giant sequoia, Tuolumne Grove, Yosemite National Park, 2017.

Several giant sequoias with other conifers in the
Tuolumne Grove, 2017.

Fire is a necessary ecological disturbance for the persistence of the species. Unlike coast redwoods which can grow semi-clonally (e.g., from burs), sequoias generally only produce new individuals from seed, though new shoots can develop from injured stumps in younger trees. Mature trees are resistant to fires of low to moderate intensity which remove understory plants and favor sequoia seed germination by exposing bare soils for germination and increasing light levels reaching the forest floor. When occurring in mixed conifer species forests, sequoias are often found with sugar pines (Pinus lambertiana) and white firs (Abies concolor). Lack of fire will promote white fir relative to giant sequoias.

Controlled fire is used today by some agencies to manage sequoia groves. Reducing woody biomass in the forest understory is a means of protecting groves from more intense large scale-fires made more likely by decades of fire suppression practices in the western US. 

With its immense size, the giant sequoia was a prized timber species in the 19^th century. Many of the 67 groves of living giant sequoia are currently protected on state or federal land. This includes three groves in Yosemite National Park and many groves in Sequoia and Kings Canyon National Parks. Additional groves within Sequoia National Forest were protected from commercial logging (which occurred up until the 1980s) with the creation of Sequoia National Monument in 2000. The groves vary greatly in size, old-growth forest extent, and logging history. The smallest of all groves is also the most northerly grove in Placer County west of Lake Tahoe. It has only 6 trees.

Panorama of the Muir Grove in Sequoia National Park, 2014. The sequoias are clustered at top center and can be distinguished from other conifer species by their slightly yellow-brown color and bushy crowns.

Sequoias are vulnerable to root disturbance and intense fires. Climate change might also present challenges to the species persistence, possibly through increasing drought impacts in the future in the Sierra. For instance, recent work by Yu et al. (2017) suggests that drought impacts may be more severe in sequoia groves than in nearby forests dominated by other tree species. However, Willard (2000) suggests that groves have been doing well recently, with many recovering from historic logging and some expanding in size.

References

Baldwin BG, Goldman DH, Keil DJ, Patterson R, Rosatti TJ, Wilken DH. 2012. The Jepson Manual. Vascular Plants of California. 2^nd ed. University of California Press, Berkeley, CA.

Eckenwalder JE. 2009. Conifers of the World. The Complete Reference. Timber Press, Portland OR.

Kusumi J, Tsumura Y, Yoshimaru H, Tachida H. 2000. Phylogenetic relationships in Taxodiaceae and Cupressaceae sensu stricto based on matK gene, chlL gene, trnL-trnF IGS region, and trnL intron sequences. American Journal of Botany 87:1480-1488.

Su Y et al. 2017. Emerging stress and relative resiliency of Giant Sequoia groves experiencing multi-year dry periods in a warming climate. Journal of Geophysical Research: Biogeosciences 122:3063-3075. Preprint link.

Weatherspoon CP. 1986. Silvics of giant sequoia. In Weatherspoon et al. Proceedings of the workshop on management of giant sequoia; May 24-25, 1985; Reedley, California. USFS General Technical Report PSW-95.

Willard D. 2000. A Guide to the Sequoia Groves of California.Yosemite Association, Yosemite National Park, CA.

Sequoias in the Muir Grove, 2014.

Cluster of female cones (left) and close-up of trunk (right), Tuolumne Grove, 2017.

Incredible plants: ocotillo

A flowering ocotillo in the western Arizona desert,
April 2017.

Primary productivity in desert environments is low. Water is the limiting resource for desert vegetation, whereas sunlight is available in overabundance. Desert plants generally only attain relatively short stature, and either flourish in annual bursts of growth (when rains come) or grow slowly over years and decades, responding opportunistically to rainfall availability over the longer term. Plants like cacti or the iconic Joshua Tree (Yucca brevifolia) of the southwest follow the latter strategy. In the life cycle of the ocotillo, one of my favorite desert plants, this species sort of embodies a bit of both strategies.

Ocotillo (Fouquieria splendens) is indicative of the Sonoran Desert, the hot low-elevation deserts of southeast California, eastern Arizona, and northwest Mexico. In terms of growth habit, the plants are one of the larger of the woody desert species in the southwestern US, reaching up to 10 m in height. They may live a century or two.

Germination of a young ocotillo requires a significant summer rainfall event of several centimeters. Most young seedlings will succumb to drought, frost or herbivores. Survivors become larger and woody. The stems of adult plants have a mottled grey and black surface with furrows. Sharp grey foreboding spines are abundant all over the stems.

Ocotillo leaves are short, spoon-shaped, and of two types. The primary leaves emerge from a petiole (which when dried, becomes the numerous spines lining the stems), while secondary leaves emerge in clusters directly from the base of the spines of the primary leaves and don’t have associated spines of their own. Secondary leaves are produced episodically and gorw in profusion very shortly after a good rain soaks the soil. The plant doesn’t invest for the long-term in these secondary leaves, rather they are produced without a cuticle (allowing easy CO₂ uptake but making them susceptible to water loss). After a few weeks mining the soil for water, the plant sheds its temporary leaves and will go physiologically dormant during a subsequent period of drought. Dormant plants retain living cells internally, but shallow roots die off and secondary leaves are lost.

Bare stem (left) on a plant from Joshua Tree National Park, CA, Feb 2012 and secondary leaves (right) on a plant from Arizona, April 2017. 

Inflorescence, western Arizona, April 2017.

Ocotillo are placed in their own plant family, the Fouquieriaceae, a small group of woody species endemic to Mexico and the southwestern US. The family is believed to have evolved in the subtropics during the Miocene (5-24 mya). The species grows below 2500 ft and occurs from California and Baja California eastward to Texas. The species is not tolerant of freezing temperatures which may be one factor limiting its occurrence in the Mojave and Great Basin deserts to the north where winter-time frost is likely.

Flowers are produced on branch tips. From a distance they appear as red flames. Flower petals are up to 2.5 cm long and are fused into a trumpet-shaped tube. A tuft of red stamens emerges beyond the corolla extending the length of the flower. Hummingbirds enjoy the nectar produced by the flowers.

References

Baldwin BG et al. (eds). 2012. The Jepson Manual. Higher Plants of California. 2^nd ed. University of California Press, Berkeley, CA.

Munz PA. 1962. California Desert Wildflowers. University of California Press, Berkeley CA.

Pavlik BM. 2008. The California Deserts. An Ecological Rediscovery. University of California Press, Berkeley, CA.

Leaf-less ocotillo in the Sonoran desert portion of Joshua
Tree National Park, Feb 2012.

New seaweed finds in central California

At the end of my trip through the southwest, I shifted from National Parks and lizards and desert wildflowers to marine life of the central California coast. At tidepooling stops in Cambria and northern Santa Cruz County, I encountered two new-to-me brown seaweed species, exciting discoveries punctuating my long-term study of natural history and biogeography along the west coast.

The first new species was a high intertidal species of rockweed at Cambria in San Luis Obispo County. Rockweeds are a family of brown seaweeds in the order Fucales. Many coastal visitors (enthusiastic about slimy seaweeds or not) have likely seen these organisms since they tend to be common on rocky shorelines and live high in the intertidal zone where a good low tide isn’t necessary to leave them exposed.

Until recently, five rockweed species were recognized along the California coast (Abbott and Hollenberg 1976; Gabrielson et al. 2004; Gabrielson et al. 2012). These species are Fucus distichus, Silvetia compressa, Hesperphycus californicus, Pelvetiopsis limitata, and Pelvetiopsis arborescens. There have been several changes to the scientific names of the California rockweeds since the publication of the landmark book on California seaweeds (Marine Algae of California; Abbott and Hollenberg 1976), so I’ve included the older Latin names in the table below.

Wandering the west coast, I have seen all five of these species at various points, the rarest being P. arborescens which is only found in the vicinity of Monterey. My visit to Cambria last month was my first encounter with the sixth rockweed species, since it was newly described in the scientific literature in a paper earlier this year (Neiva et al. 2017). Maybe I have seen it before without recognizing it as a distinct species.

Two common rockweed species in California: Fucus distichus (left; Carmel Pt., Monterey Co., 2014) and Silvetia compressa (right; Scott Creek, Santa Cruz Co., 2007).

Traditionally species have been described based on their morphology, but increasingly molecular signatures are complementing, and even upending, traditional concepts of differences between species. Neiva and colleagues examined mitochondrial DNA from Pelvetiopsis and Hesperophycus, identifying a new species of Pelvetiopsis: P. hybrida.

Neiva et al.’s study resulted in some other interesting findings. First, they found evidence that P. hybrida originated because of a relatively recent hybridization event between Hesperophycus californicus and Pelvetiopsis arborescens. Up until this study, the authors note, this type of hybridization (allopolyploidy) has probably never been documented before in brown seaweeds. Polyploidy refers to chromosome multiplication inside the nucleus during a hybridization event (for instance, a hybrid progeny has twice the number of chromosomes as its parents). Allopolyploidy occurs when the two parents are from different species.

Second, the researchers confirmed that P. arborescens is a distinct species genetically, and suggested that its restricted range indicates it is a climatic relict. Finally, they found that the evidence didn’t favor placing Hesperophycus on its own separate branch on the evolutionary tree. Instead this genus seemed to stem from within the Pelvetiopsis branch, meaning that it should be renamed to be a part of that group. Hesperophycus californicus was this renamed to P. californicus in the study. 

Pelvetiopsis spp. along the US west coast. Clockwise from upper left: P. limitata (Dillon Beach, Marin Co., CA, 2008), P. californicus (Cambria, San Luis Obispo Co., 2017), P. hybrida (Cambria, 2017) and P. arborescens (Carmel Pt., Monterey Co., CA, 2017).

All those scientific name changes, annoying as they can be when trying to be a diligent student of natural history, are part of the evolution of scientific understanding and hopefully bring us to a better picture of the true evolutionary relationships among organisms over time. So, the current names for the (now) six species of California rockweeds are below:

Note that Silva et al. (2004) recognize two subspecies of Silvetia compressa: S. compressa ssp. compressa on the mainland coast of North America and S. compressa ssp. deliquescens on the Channel Islands in southern California.

At Cambria, the high intertidal rocks had populations of P. hybrida where it was pretty common. I photographed the species pretty intensely, noting that they seemed different from the usual Pelvetiopsis limitata (this species is the most common and widespread of all the species in the genus where I tend to tidepool), but I wasn’t confident I was really seeing the new species until I returned home and reviewed Neiva et al’s paper. Perhaps unsurprisingly because it is a hybrid lineage, P. hybrida is morphologically intermediate to its parent lineages. It has some cryptostomata (tufts of very small colorless hairs on the surface of the plant) like Hesperophycus, but its branches are narrower, intermediate between the two parental species. 

A mix of four intertidal rockweed species at Point Pinos, Monterey Co., 2016. Can you identify the four species?

~ ~ ~ ~

My second new seaweed find got me really excited. It was a kelp, another group of brown seaweeds in the order Laminariales. Kelps are one of my favorite groups of marine plants and after about two decades of tidepooling along the west coast, I think I’ve seen virtually every species that occurs between San Diego to Washington…except one. That would be the elusive Laminaria ephemera.

I’ve seen L. ephemera as a herbarium specimen to be sure, but until this spring I had never seen it in the wild. The magic location was Greyhound Rock in northern Santa Cruz County.

As I often do during rocky intertidal visits, I was compiling a list of large brown seaweeds (Laminariales, Fucales, etc.) present at the site, when I stumbled upon a few long kelp blades in the low intertidal that didn’t immediately register as a known species. The blades were entire (not divided), long, slender, and simple except for a really pronounced sorus (area of spore production) at the center of the blades. I initially thought of Laminaria farlowii, but the blades of that species are distinctly ruffled all over its surface. And then my mind settled on Laminaria ephemera, a species I had long known about but had never positively identified in the field.

The key feature to identify L. ephemera lies in the holdfast. Unlike most other kelp species, it has a discoid holdfast that lacks haptera (spreading branches that superficially resemble plant roots). The holdfast is essentially a small golden brown suction cup that anchors the plant to a rock. Gently moving aside some of the algal cover around the base of the plant, sure enough, I could see the small smooth holdfast.

Laminaria ephemera at Greyhound Rock, Santa Cruz Co., CA, April 2017. Left: Blades. Right: close-up of discoid holdfast.

The population of L. ephemera I discovered was of unknown size, but it didn’t seem large from my observations. There were about 10 blades that seemed to meet the visual criteria for the species, and I checked about half of those to verify the presence of the correct holdfast. There were smaller kelp blades in the low intertidal that could have been less mature plants of the species, or possibly specimens of L. sinclairii or L. setchellii, both of which were also present at the site. The challenge with identification of the kelps is that the juvenile sporophytes all look terribly similar, regardless of species.

Two blades of L. ephemera with sori (regions of a seaweed blade that produce spores) at Greyhound Rock, April 2017.

How would a large seaweed like L. ephemera be hard to miss? A few reasons perhaps. First, as one of the few annual kelps, L. ephemera would quickly mature and then disappear after several months of growth. It would be an unlikely find in the fall or winter. Second, blades might be easily confused for small plants of L. setchellii (before the blade begins to divide into individual straps) or L. sinclairii. One would have to check every holdfast to distinguish L. ephemera from related kelps. Finally, L. ephemera appears to be fairly rare along the west coast of the US. Abbott and Hollenberg (1976) note that it is present from Alaska to Monterey County, but also call it “infrequent”. Reviewing herbarium records available on-line at the Macroalgal Herbarium Portal, in California this species seems to have mainly been collected from Monterey and Humboldt Counties, so my finding of a small population in northern Santa Cruz County may possibly be a new location for this species. This is a species I’d like to study further in terms of prior collections, and … I need to check more kelp holdfasts in the field!

References

Abbott IA, Hollenberg GJ. 1976. Marine Algae of California. Stanford University Press.

Gabrielson PW, Widdowson TB, Lindstrom SC. 2004. Keys to the seaweeds and seagrasses of Oregon and California, north of Point Conception. Phycological Contribution No 6.

Gabrielson PW, Lindstrom SC, O’Kelly CJ. 2012. Keys to the seaweeds and seagrasses of southeast Alaska, British Columbia, Washington, and Oregon. Phycological Contribution No 8.

Macroalgal Herbarium Portal. 2017. http://macroalgae.org/portal/index/php. Accessed 16 May 2017.

Neiva J, Serrão EA, Anderson L, Raimondi PT, Martins N, Gouveia L,Paulino C, Coelho NC, Miller KA, Reed DC, Ladah LB, Pearson GA. 2017. Cryptic diversity, geographical endemism and allopolyploidy in NE Pacific seaweeds. BMC Evolutionary Biology 17:30.

Silva PC. 1990. Hesperophycus Setchell & Gardner, nom. cons. prop., a problematic name applied to a distinct genus of Fucaceae (Phaeophyceae). Taxon 39:1-8.

Silva PC, Pedroche FF, Chacana ME, Aguilar-Rosas R, Aguilar-Rosas LE, Raum J. 2004. Geographic correlation of morphological and molecular variation in Silvetia compressa (Fucaceae, Fucales, Phaeophyceae). Phycologia 43:204-214.

Incredible plants: Codium

Most marine seaweeds can be classified into one of three groups of algae: reds, browns, or greens. The ancestors of today’s green algae are the group from which all modern land plants (mosses, ferns, and seed plants) evolved. Green algae are widespread globally; they are found in freshwater aquatic habitats, terrestrial environments (for example, some form symbioses with lichen-forming fungi), and of course in the oceans.

Codium fragile (upper right) and C. setchellii (throughout
photo) on intertidal rocks at Carmel Point, Monterey Co.,
CA, December 2016.

One fascinating group of green algae is the coenocytic greens. The term ‘coenocytic’ refers to an organism that technically consists of only of a single cell. Plants and algae have cell walls outside their cell membranes that provide structure to tissues. In coenocytic algae, a cross-wall does not fully form between the two daughter cells resulting from cell division. Replication of the nucleus (karyokinesis) occurs normally as with other organisms, but is not followed by complete cell division (cytokinesis). Many of the coenocytic algae are centimeters or decimeters in length, which makes the thought of them being a single cell quite remarkable!

Coenocytic species are common in marine green algae (Class Ulvophyceae, Division Chlorophyta). Examples include Bryopsis and Caulerpa. Many of these species are also called “siphonous” green algae. Other coenocytic macroalgae are calcified (Dasycladales) and grow in tropical coastal oceans.

One globally-distributed coenocytic green is the genus Codium. The distinctive color, texture, and shapes of Codium plants make them pretty easy to recognize in the field. They are true green algae, but in the field they are sometimes such a dark green color that they appear almost black.

Submerged Codium fragile in a tidepool at Davenport Landing, Santa Cruz
Co., CA, November 2009.

Along the Pacific coast of North America, there are several species of Codium. The two that I have encountered while tidepooling are Codium fragile and C. setchellii. C.fragile is a branching species and it has the notorious common name of “dead man’s fingers”. The branches are not in fact wide enough to resemble a human finger, but when the plant lays limp on the side of a rock at low tide, the common name is none-the-less reasonably accurate.

C. setchellii has a very different growth form than C. fragile. It grows like a velvet cushion, tightly adhering to the rock surface. C. setchellii has the common name of “green spongy cushion”, but I think the common name “dead man’s brains” might be a good alternative if we were to keep with the morbid theme.

The Hawaiian flora has 15 species, including both prostrate and branching growth forms.

The plant body of Codium consists of many intertwined filaments, which again are technically a single sell. On the outer surface of the seaweed’s body, the filaments end in a structure called the utricle. Utricles are the site of photosynthesis for the plant. Some utricles are pointed and some are flattened at the tip.

Utricles of Codium sp. under magnification, unknown date.

The next time you are tidepooling on Halloween (or any time of year), be sure to look for dead man’s fingers or dead man’s brains!

References

Abbott IA, Hollenberg GJ. 1976. Marine Algae of California. Stanford University Press, Stanford, CA.

Abbott IA, Huisman JM. 2004. Marine green and brown algae of the Hawaiian Islands. Bishop Museum Bulletin in Botany 4. Bishop Museum Press, Honolulu.

Druehl L 2000. Pacific Seaweeds. Harbour Publishing.

Lewis LA, McCourt RM. 2004. Green algae and the origins of land plants. American Journal of Botany 91:1535-1556.

Lobban CS and Harrison HJ. 1997. Seaweed Ecology and Physiology. Cambridge University Press.

Sze P. 1998. A Biology of the Algae. 3^rd ed. WCB McGraw-Hill. 

Population of C. fragile growing in the intertidal at Botany Beach, Vancouver
Island, BC, summer 2000. The distribution of these plants in a vertical band
is an excellent example of intertidal zonation.

Incredible plants: The Proteaceae

Organisms come in all shapes and sizes, even within groups of closely related species. The processes of evolution – selection and drift – have produced wonderful variation in the morphology (shape) of plant and animal organs, whether they are wings, leaves, flowers, or exoskeletons.

                                                                  

The Proteaceae are a striking example of what evolution has accomplished with morphological variability. These plants sometimes look like species out of an imaginary world in a children’s book. Flowers in the family are especially interesting and are popular for cultivation. Some flowers are shaped like bottle brushes, others like giant dishes of radiating color. Leaves can be shaped like little lances, or deeply dissected, or jagged like a saw tooth. The genus from which the family derives its name, Protea, was given its name by Linnaeus who invoked the Greek god Proteus, a deity capable of changing his shape.

Banksia menziesii, native to Australia. Photos taken at UC Santa Cruz Arboretum.

Protea scolymocephala. Photo taken by Andrew Massyn,
public domain.

The Proteaceae are believed to be an old family of flowering plants, evolving at least 140 million years ago. The family originated on the ancient southern hemisphere super-continent of Gondwanaland. Over time that large land mass split apart into the continents of Australia, Africa, South America, and Antarctica. Today Proteaceae are found on most of these southern hemisphere continents, an indication of their ancient origin and the effects of continental movement on the modern day distribution of species across the globe.

The showy inflorescences common in the family attract a lot of attention. Flowers are typically born in groups arranged in a spike. In some genera like Banksia, the inflorescence is a tall column of brightly colored flowers perched on the plant’s branches. The individual flowers in the family are composed of 4 parts which are fused into a perianth to varying degrees. (The perianth refers to the combined structures of petals, sepals or tepals in a flower.) Some flowers are tubular in shape. Most species have bisexual flowers, where both male and female parts are present in the same flower. The flowers have four stamens, which sometimes emerge directly from the perianth. The female part of the flower is a long prominent style ending in a stigma that functions to capture pollen. Nectar glands are often present too.

Grevillea spp at the UCSC Arboretum. Bee pollinating Grevillea sp (left); G. levis (right).

Mimetes cucullatus, native to South Africa.
Photo from UCSC Arboretum.

Proteas rely on different strategies or vectors for pollination. A few species are wind pollinated or visited by mammals. Flowers that are red and produce nectar tend to rely on birds for pollination. In contrast, insects typically pollinate flowers that are white, blue, or purple in color. Conospermum is an insect-pollinated genus that has an “explosive” pollination mechanism that accomplishes two tasks: obtaining pollen from another flower, and preventing its own stigma from being self-pollinated (self-pollination inhibits exchange of genetic material between individuals). To accomplish this, the style is initially bent backwards inside the flower keeping the stigma away from its own pollen. When an insect visits the flower, the stigma snaps forward hitting the insect, thereby picking up pollen on the insect’s body that it acquired from another flower. The snapping motion of the style also ends up dusting the insect with pollen from its own flower which can then be transferred to another plant.

Proteas tend to share some ecological commonalities. They are trees or shrubs and all have at least some woody tissues. They tend to grow on sandy or gravel soils that are low in nutrients, especially phosphorus. Species in the family often grow in drier habitats, but they have adaptations to minimize water loss. Many have tough leathery leaves that contain a lot of lignin but few nutrients, making them a less favorable food choice for herbivores. Leaves tend to be long-lived since producing them requires significant investment of resources by the plant. Some species such as Leucospermum have leaves that secrete nectar.

Remarkably, proteas lack the symbiotic fungi that associate with the roots of most terrestrial plant species (mycorrhizae). Mycorrhizae are beneficial to plants because they help with nutrient acquisition. In place of mycorrhizae, many proteas have evolved a different type of root adaptation to acquire soil nutrients. Plants form clumps of small dense rootlets that grow near the soil surface called “proteoid roots”. These roots develop in response to rain and may only last for a few months.

Banksia nirida at UCSC Arboretum. Leaves and inflorescence (left); close-up of inflorescence (right).

Some proteas live in fire prone areas and thus need adaptations to survive fires. These adaptations include recruitment of a new generation of plants from seed following fire, or recovery of above-ground shoots from tubers or “boles” that live below-ground. Boles are underground stems from which new above-ground growth can occur. By having thick bark or by growing isolated in outcrops of rock, plants can also escape fire damage. Some paleobotanical evidence from central Australia suggests that fire-prone biomes with Proteaceae present in the plant communities may be very old, stretching back to the Cretaceous period (Carpenter et al. 2015).

Leucadendron discolor, native to South Africa. Photo
taken at UCSC Arboretum.

Estimates of species diversity in the Proteaceae range from about 1250 to over 1500 species. About 70 genera are recognized. The greatest diversity is found in Australia, where there are representatives of all 5 subfamilies. In fact, because of its high modern-day diversity, it is believed that the family evolved in the region of Gondwanaland that would later become Australia after fragmenting. South Africa is the second most diverse region for the family, with about 330 species and 14 genera. In fact, the “Cape Floral Kingdom” in South Africa is one of the most diverse regions on the planet for vascular plant diversity. One reason for the high diversity may be the high degree of topographic variation (mountains and valleys with different soil types and climates) in that region. The distribution of some high elevation species in the area, including some Proteaceae, may reflect species taking refuge in climatic conditions that they once evolved in long ago (Verboom et al. 2015).

In my opinion, the Proteceae also have some of the coolest common names. Scientists traditionally use Latin scientific names (binomials) because they help reduce confusion and identify some of the shared relationships of species within genera, but I certainly don’t mind the common names of the Proteaceae. Some examples of names from South African plants include:

-          Protea (smokebushes)

-          Serruria (spiderheads)

-          Vexatorella (vexators)

-          Mimetes (pagodas)

-          Orothamnus (marsh rose)

-          Pranomus (scepters)

-          Spatella (spoons)

-          Diastella (silkypuffs)

-          Hakea (needlebushes)

The most widespread human use of proteas is perhaps the flower trade. Another commercial use, which I was surprised to learn involves the family, is the fact that macadamia nuts are produced by two species of Proteaceae: Macademia integrifolia and M. tetraphylla. Originating from Australia, these species were introduced into Hawaii in the late 1800s for macadamia nut cultivation. Later, the industry spread to Africa, California, central America, and then finally developed back in Australia. The native aboriginal people of Australia also used some proteas for food. Some Dryandra and Hakea species are involved in honey production. Finally, a few species in Australia have been used for timber. Like many groups of organisms, Proteaceae face conservation challenges. For instance, in South Africa, about a third of proteas are threatened.

Macadamia integrifolia in cultivation on Maui, Hawaii. Left: flowering trees. Right: macadamia fruits and nuts. Images by Forest and Kim Starr, cropped and arranged by C. Janousek, under CC Attribution 3.0 Unported license. Original photos here, here, and here.

I’ve never observed the Proteaceae in their native habitats, but I hope that will change in the future. A botanical trip to South Africa or Australia would be amazing! However, the Arboretum at UC Santa Cruz has a wonderful collection of southern hemisphere plants including species of Banksia, Protea, and other representatives of the family. The plants grow well in central California presumably because of the shared Mediterranean climate with other regions where Proteaceae grow. A walk through the paths of Banksia and other species is a pleasant journey to another botanical world unfamiliar to us in North America. The Arboretum also has quite a few species for sale at reasonable prices, and I could not pass up the chance to buy a few!

Ecologically, morphologically, and even mixed into your chocolate chip cookies, the Proteaceae are incredible plants, a botanical treasure from the southern hemisphere!

References

Carpenter RJ, Macphail MK, Jordan GJ, Hill RS. 2015. Fossil evidence for open, Proteaceae-dominated healthlands and fire in the Late Cretaceous of Australia. American Journal of Botany 102:2092-2107.

George AS. 1984. An introduction to the Proteaceae of Western Australia. Kangaroo Press, Kenthurst, Australia.

Rebelo T. 1995. Proteas. A field guide to the Proteas of southern Africa. Fernwood Press.

Sainsbury RM. 1991. A field guide to smokebushes and honeysuckles (Conospermum and Lambertia). University of Western Australia Press.

Verboom GA, Bergh NG, Haiden SA, Hoffman V, Britton MN. 2015. Topography as a driver of diversification in the Cape Floristic Region of South Africa. New Phytologist 207:368-376.

Wrigley JW. 1989. Banksias, Waratahs and Grevilleas and all other plants in the Australian Proteaceae family. Collins Publishers Australia.

Banksia victoriae. Inflorescences and saw-tooth leaves (left); close-up of inflorescence (right). Photos from UCSC Arboretum.

Incredible plants: tiger lilies

Lilium columbianum, near Comet Falls, Mt. Rainier
National Park, July 2016.

Lilies are a stunning group of flowering plants, and many members of that family have a strong aesthetic appeal for me. The Liliaceae are monocots, thus the flower parts occur in multiples of three. A prototypical lily flower would have six petals, six stamens, and a single style protruding from the center of the flower. Several lilies such as some members of Calochortus and Lilium have a curved perianth (petals), so that the overall shape of the flower is like an orb.

“Tiger lily” is an informal common name which has been applied to a few species in the genus Lilium that have orange spotted petals. These include Lilium columbianum (the “small-flowered tiger lily”), two subspecies of L. paradalinum (“Vollmer’s tiger lily” and “Wiggins’ lily”), and L.parvum (“Sierra tiger lily”) (Turner and Gustafson 2006; Skinner 2016). Other similar species in the Pacific states include L. bolanderi and L.occidentale, each with reddish spotted petals. 

Characteristics and distribution of five "tiger lily" species in the Pacific states.
References: Turner and Gustafson (2006), Baldwin et al. (2012), Wenk (2015).

Shoots of these lilies are typically 1-3 meters in height, green (non-woody), and have whorls of leaves emerging from the stem at regular intervals. The flowers of some species including L. columbianum and L. paradalinum hang pendant, a humble posture unnecessary for such a glorious flower.

Lilium pardalinum. Left: Ventana Wilderness, Los Padres National Forest, Big
Sur, CA, 2009. Right: Sucker Creek, Siskiyou National Forest, southern OR, July 2016.

Of the five species listed here, L. columbianum is most common, being distributed from British Columbia to northern California (Turner and Gustafson 2006). L. pardalinum occurs in California and southwest Oregon, while L. bolanderi and L. occidentale inhabit the Klamath mountains area in northwest CA and southwest OR (Turner and Gustafson 2002, Baldwin et al. 2012). L. parvum inhabits wetland or riparian areas at higher elevations in the Sierra range (Baldwin et al. 2012).

Lilium parvum, Tahoe National Forest, Sierra Nevada range,
CA, July 2009.

While visiting Oregon Caves National Monument earlier this summer, we camped along Sucker Creek, a quiet beautiful location where the shallow stream ran swiftly among rocks, close to the campsite. Riparian corridors seem to be excellent locations to find tiger lilies and I spotted some flowers along the far bank of the river. I crossed over to photograph them. The first flowers were somewhat on their way out, but farther upstream I found a cluster of several plants at the edge of the river near a rocky outcrop of serpentine, each bearing several flowers in their prime.

The green hues of serpentine rock and beautiful blooming lilies were exciting enough, but suddenly I also noticed a beautiful swallowtail butterfly visiting the flowers too. It was photographic bliss to have two such bright and magnificent organisms in the same place. The swallowtail was mostly undeterred by my close presence and spent some time visiting a few different flowers. It landed on the underside of each flower and then rhythmically bowed to the flower, each time inserting its long black proboscis deep into the flower to extract nectar.

Lilium pardalinum and a beautiful swallowtail visitor at Sucker
Creek, Siskiyou National Forest, southern OR, July 2016.

References

Baldwin BG et al. 2012. The Jepson Manual. Vascular Plants of California. 2^nd ed. University of California Press, Berkeley, CA.

Skinner MW. 2016. Lilium parvum, in Jepson Flora Project (eds.) Jepson eFora, http://ucjeps.berkeley.edu

Turner M, Gustafson P. 2006. Wildflowers of the Pacific Northwest. Timber Press, Portland, OR.

US Geological Survey. 1996. Kerby Peak, OR. 1:24000 topographic map.

Wenk E. 2015. Wildflowers of the High Sierra and John Muir Trail. Wilderness Press, Birmingham, AL.