When I saw this field of plants in the white sand of the Jurien Bay area, I was rather sure it was a member of Restionaceae. The male plants were easy to see, with their small brownish conelike inflorescences, but where were the female flowers? This is the new genus, Alexgeorgea.
Seen at ground level, the male plants of Alexgeorgea in the background and their light brown inflorescences are obvious. But what I saw at ground level had never been seen before—a trio of purple threads emerging from the sand (foreground). These stigmas are the only portions of the female flowers that ever emerge above the ground.
The very slender stigmas emerge from a narrow tubular sheath of bracts. The purple portions of the bracts—just the tips of them—may break through the surface of the sand. The tube of bracts has the function of protecting (and directing) the styles on their way to the surface. If not so protected and directed, the styles would probable reach the surface damaged, if they reached it at all.
A female plant of Alexgeorgea excavated from the sand. Here’s the story: there are horizontal underground rhizomes that stay about 10 cm beneath the surface of the sand. Vertical shoots—green above the surface of the sand—grow upwards from the horizontal rhizome. Restionaceae are leafless, but the stems photosynthesize. Also borne on the horizontal rhizome are female flowers, sheathed in a tube of papery bracts. The female flowers are sessile on the rhizome, so that the ovary is actually borne right on the rhizome. The belowground parts of the plants are white.
So here’s the story of Alegeorgea summarized—the aboveground parts lined up here for the purpose of a photograph. At left, the aboveground shoot of a male plant, with inflorescences on it. Center, the aboveground shoot of a female plant—these shoots of female plants look like those of the males but have no flowers. At right, the stigmas and narrow tubular sheath of bracts around them. The female flower has been inserted into the sand for the purpose of this lineup: the bract sheath should have been inserted more deeply (the transition between white and purple in the bracts is where the soil surface is).
The single-seeded fruit of Alexgeorgea. About the size and shape of an acorn, it is borne sessile on the underground horizontal rhizome. The fruit is thus well beneath the surface of the soil, and thereby escapes fire. And it also escapes predation.
The amazing flower of Stylidium and how it works. Appendages or colorful markings in the throat attract a Comptosia fly and guide it to nectar which is borne in the corolla tube. While feeding, the fly triggers the column it, which in the case of this species S. crossocephalum), hits the fly on its back. The first day that a Stylidium flower is open, the four anthers at the tip of the column are capable of shedding pollen, which thus gets dusted on the fly’s back when the column is triggered. The column then repoises and is capable of being triggered a second time. The second time, the stigma tends to be grown out from among the anthers, and forms a cushion that can pick up the pollen from an insect’s back: that is the stage shown in this photograph.
In the sand heath at Cape Le Grande, the species I named S. macranthum is very common. This plant had been noticed before, but it had just been identified as belonging to a species that is actually quite different from it..
The throat of S. macranthum has a pair of winglike appendages and four other pointed appendages: these have the function of directing the fly towards the nectar, and therefore could be called nectar guides. Possibly, they could exclude insects that would not be effective in pollination.
The fifth corolla lobe of a Stylidium, called the labellum, is recurved and can be seen on the outside of the corolla tube. The central portion is always shiny in Stylidium, and looks like a drop of nectar—it may, in fact, be a false nectar lure. In S. macranthum, the labellum has a pair of pink lateral appendages. The labellum may help direct an insect not merely to nectar but to the part of the column that is sensitive to touch and triggers the column movement.
At some time (a day or two) after the anthers have shed pollen, the stigma begins to make its appearance between them. The stigma is greenish-white here. External to the anthers are some shiny hairs, the function of which is not certain yet. (S. macranthum).
The tip of the column of Stylidium macranthum, seen from the surface opposite that on which the anthers and stigma are borne. The glistening hairs do not belong to the stigma. Such hairs may be false nectar lures in some plants, and perhaps they are in Stylidium. Nobody knows. The flowers of Stylidium do offer nectar, so false nectar lures are not likely to be disregarded by a pollinating insect, especially if the nectar lures direct the insect.
Stylidium inversiflorum is distinctive in that the column, instead of coming down from the top of the flower and hitting an insect on the back, comes up from below and hits the insect on the lower surface of the abdomen. This positioning, opposite from that of S. macranthum, is achieved by a 180° twist in the pedicel.
If one digs up a plant of S. insensitivum, one sees that the leaf bases are swollen, and thereby a bulb is formed. These structures permit S. insensitivum (and related species, such as S. petiolare) to survive the hot and dry summer months.
The front of the flower of S. insensitivum reveals the yellow and purple markings in the throat: these are doubtless markings that attract the fly that pollinates it to the nectar in the corolla tube.
A side view of a flower of S. insensitivum. The column is very short and is immobile, whereas the related species all have sensitive columns that can be triggered. The column in this flower shows the stigma.
A side view of a flower of S. insensitivum, shown with the fly I found visiting the flowers in abundance. This flower is probably in a pollen-shedding stage; the hairs at the end of the column do not belong to the stigma.
There is not much to say about this tiny ephemeral Stylidium, which I named S. roseonanum, except that it is small, even compared to the other species in the species group to which it belongs, and that it has several distinctive characteristics. Ephemeral species of Stylidium can grow to flowering and form seeds in a few weeks. This habit is advantageous on sites that dry rapidly.
The center of this flower of S. squamosotuberosum reveals that throat appendages are absent. Distinctive markings in the throat of the corolla tube are the result of differential presence and color of cell contents. Notice the abundant nectar in the tube.
The unusual basal stem of S. squamosotuberosum, covered with scale leaves, gives S. squamosotuberosum its name. Storage in a thickened stem is unusual in the genus, and no other species has a tuberous stem that looks like this one.
A flower of S. expeditionis shows several distinctive features: the upper corolla lobes are larger than the lower ones, and form a sort of reverse-hooded conformation. The column is rather small compared to the columns of related species.
The flowers of S. simulans resemble those of another species, S. lobuliflorum, but that species is not closely related. Probably this is a case of floral mimicry, where flowers of one species resemble those of another with which it grows. By being very similar, the flowers of two species can attract the same pollinating insect.
The fruits of S. simulans are slender: when they break open, the fruit walls bend back, exposing the seeds. The small size of seeds of most Stylidium species—about the size of grains of sand--would seem to make them suited for wind-dispersal.
S. nominatum grows with a species of Mitrasacme, which belongs to Gentianaceae. The flowers are very similar in size and coloration. Because the Stylidium resembles the Mitrasacme so closely, I named it S. mitrasacmoides. A gaffe—the name S. mitrasacmoides had already been used (it probably is a synonym of S. alsinoides). So I had to rename the species, and I chose the name S. nominatum (the “already named” Stylidium). In doing so, I remembered the botanist who named a new Ribes species, but twice is succession, picked a species name that had already been used in Ribes—so the third time he named it Ribes binominatum (the “twice-named” Ribes).
Flowers of S. dunlopianum, named for Clyde Dunlop, who discovered it. The column has distinctive flanges on it. This photograph shows bunches pollen grains on the face of the column. This flower is in a late stage of anthesis, and shows the stigma fully grown out.
This is Stylidium evolutum as seen in the field, south of Darwin. It differs from S. tenerrimum in a number of characters. Stylidium evolutum is upright, not trailing. It has sessile, not pedicillate flowers. The capsules are not constricted at the base.
The flower of Stylidium evolutum is distinctive in the genus: the petals are united in pairs laterally, but one pair is much smaller than the other, and the column operates horizontally. Other species in which the column operates laterally do not have this marked differentiation between the two pairs of corolla lobes. The flowers are relatively large, and red blotches extend across the corolla lobe bases. The throat of the flower bears a yellow collar. In S. tenerrimum, the flowers are minute, without any throat appendages, and there are spots rather than wide bands at the bases of the corolla lobes.
This is a flower of a species I named S. curtum. The corolla is much shorter than the corolla; the column is red even at the base. Stylidium curtum has a labellum on the outer surface of the corolla tube, as in S. pedunculatum, but—a feature that has been overlooked—S. curtum is apparently the only species of Stylidium to have a “pseudolabellum,” a toothlike fifth corolla lobe at the bottom of the sinus. The corolla of S. curtum does not open out, but surrounds the column in a tubelike fashion. The leaves of S. curtum are sparsely hairy; the hairs are only half the length of the hairs on leaves of plants called S. ericksoniae; leaves of S. pedunculatum are glabrous (essentially the only constant difference between the latter two species). The fact that corollas of S. curtum are so small and do not open outward at anthesis suggests that autogamy is complete, and that there is therefore no selection for a corolla attractive to pollinators.
Here’s a flower of S. pedunculatum for comparison with those of S. curtum. In S. pedunculatum, the corollas are open conspicuously at anthesis, and are lavender on the inside, yellow outside, and are longer than the column. No pseudolabellum is present. The column is white at the base.
Like Stylidium, Levenhookia has a column, and each species has distinctive throat markings that attract an insect visitor. The flower of L. pulcherrima is seen here in face view. The petal sizes, shapes, and colors also differentiate species of Levenhookia.
A side view of the flower of L. pulcherrima illustrates the distinctive column of Levenhookia. It is held within the globular pale violet-colored labellum, and when an insect forages for nectar, it springs up, catapult-fashion. The anthers are seen at the tip of the column in this view.
A flower of L. pulcherrima at a later stage shows the column with the minute finger-like stigmas grown out at the tip. The stigma positions seen here are characteristic of L. pulcherrima—other species differ in that respect. The column does not repoise once triggered—a prominent difference between Stylidium and Levenhookia.
NEW SPECIES AND A NEW GENUS
The new genus. It’s a funny story. It really begins in South Africa in 1973. When I was doing field work there for nearly six months, I had the enormous privilege of doing field work with Elsie Esterhuysen. At various points in the world, there is a botanist who has an encyclopedic knowledge of a regional flora. Elsie Esterhuysen was such a person; her knowledge of the flora of Cape Province was amazing. When I arrived in South Africa and announced my interest in looking for Bruniaceae, she was the person to see. She knew where they all were. More importantly, she knew where the trails to these plants, which mostly grow in the mountains of South Africa (often only in the summit areas of those mountains!) were. I would never have found the trails, much less the plants, without her. Elsie lived an ascetic life, and did not own a car. She probably dedicated all of her resources to the banishment of apartheid in South Africa and was sure that she was under government surveillance. Because she did not own a car, and because I did rent a VW beetle, and because she was still eager to do field work in Cape Province, she expressed an interest in joining me in my field work. We ranged over the fynbos areas of Cape Province together, climbing something like 44 mountains together (some of those mountains were less than 1,000 m, but many of them were about 1,000 m high). I did collect Bruniaceae, but I kept my eyes open, collecting other things also—a habit of mine during field trips. As for Elsie, her declared specialty was Restionaceae, that southern hemisphere family of plants with a vaguely sedgelike appearance. She knew all of the South African species of the family, and even pointed out some new species of them along the way. I decided that I might as well learn about this family from her, and so I tried to keep track of the restionaceous genera (but not all of the species) that we saw together. A great privilege.
Most of the species of Restionaceae outside of South Africa are in Western Australia, which has extensive acid sand areas comparable to the acid Table Mountain sandstone areas of Cape Province. The year after I was in South Africa, I spent four months in Western Australia. I had not intended to spend that time in Western Australia, but Alex George had invited me join him and some other CSIRO staff in a trip to the central deserts of Australia, because the rainfall had been exceptional. I accepted, and the giant circle trip from Perth to Giles and back was a great adventure. After the trip, I undertook field work in the Southwest of WA. Larry DeBuhr joined me in order to collect materials for his Ph.D. thesis on Drosera while I collected—whatever. I was collecting wood of several families (Gyrostemonaceae, Chloanthaceae, and Pittosporaceae, for example), and I was enjoying my hobby of looking at Stylidiaceae of the region and seeing if I could discover some new species there.
One morning, Larry and I were on the great sandplains in the Jurien Bay area, when I noticed here and there the green upright shoots of an inconspicuous plant I thought might be a restiad. I noticed plants with male inflorescences on them. I had learned from Elsie Esterhuysen that in order to identify Restionaceae, one must collect both male plants and female plants in flower, and also female plants in fruit. I was reasonably sure that this plant belonged to Restionaceae, so after finding the male plants, I looked for female plants. I couldn’t seem to find any. I think I had given up, or was merely looking around on the sand surface at other plants, but I spotted a group of three divergent purple threads emerging from the sand. Then, here and there, a few more such purple thread triads. I immediately realized that these had to be stigmas, and that the female flowers were underground. I began to dig in the sand with my hands to locate the flowers. About 10 to 13 cm. under the sand surface, there were horizontal white rhizomes, and the female flowers were, at intervals, borne sessile on thee rhizomes. On older portions of the rhizomes, there were fruits, about the size and shape of acorns, sitting on the rhizomes. The fruits were thus borne underground—and presumably stayed there, unless the sand shifted and uncovered them, or some animal dug them up. The female plants had green aboveground shoots that looked like those of the male plants. Before I dug the female plants up, I hadn’t noticed that some of the green shoots bore male inflorescences (tiny conelike structures), and some didn’t. I now realized that the green aboveground shoots not bearing male inflorescences belonged to female plants.
I decided to name the new genus Alexgeorgea, in honor of Alex George, who had been kind to me during my travels in Western Australia [ PDF ]. I have publicized this plant with the oxymoron, “the world’s first wind-pollinated plant with underground flowers,” which may be a bit misleading. The most important feature, of course, is the underground position of the female flowers and fruits. The truly startling implication is that Alexgeorgea has evolved a method for bearing the fruits underground where they are least likely to experience damage from fire—and probably also escape predation. The selective pressure for plants to survive fires in some way is enormous in Western Australia. Not far from the Alexgeorgea colony I discovered is a stand of Actinostrobus acuminatus, a conifer with all of its cones borne at ground level. The genera Banksia and Dryandra are represented in southwestern Australia by species in which the stems are underground, but leaves extend aboveground and inflorescences are borne at ground level. Some plants in southwestern Australia flower only after a fire (notably Drosera and many orchids), and the small seeds of these plants thus escape heing burned. The fruits of many species of Hakea are large and corky, and open only after fire. There is some fire survival story in every plant in Western Australia.
Stylidiums of Southwestern Australia. (see pictures) During my first visit to Western Australia, in 1962, I was attracted by the triggerplants, Stylidium, which have such a fascinating pollination mechanism. I admit it: when I visit a place, I want to know, at least superficially, what all of the plants are (for this reason, I should not and rarely have visited tall rain forest). In a bookstore in Perth, I found Rica Erickson’s wonderful little book, “Triggerplants,” published in 1958, which covers all of the Stylidiaceae known at that time. Rica Erickson was an amateur who enjoyed collecting and very accurately drawing the species of Stylidium and Levenhookia. The illustrations are very accurate, because they were done from living specimens. The descriptions—aided by Mildbraed’s monograph in Das Pflanzenreich—are also accurate. But in addition, the book has the appealing charm that only someone genuinely enthusiastic about a hobby can confer. It seems to invite one to identify and learn about the triggerplants of southwestern Australia—and indeed, they have speciated in spectacular fashion there. So I accepted that invitation, as it were, and identified the species I found in 1962. In fact, I began to find some new species—especially in 1967 (the species were published in 1969) and again in 1974 [ PDF ]. During my 1974 visit, I photographed the new species I had located in 1967, because I had improved my photographic techniques. The way to recognize new species in any genus is to be able to recognize all of the ones that are currently known. I was rather amazed that I was able to locate so many new species. How could they have been overlooked? The answer was very simple. Aside from Rica Erickson, nobody in recent time had been interested in them with respect to taxonomy. One must remember that Western Australia is a remote part of the world to most people, and that in the 1960s and 1970s, few botanists worked there. Also, it is an area enormously rich in species, because there is a wide range in climates from desert to wet eucalypt forest, with an insular distribution of soil types—islands of acid sand within alkaline laterites, or vice versa. Stylidiaceae are not conspicuous, and the large number of species probably tended to discourage most botanists from trying to identify them. The new species I discovered in the field were all found not far from roads. Paved roads, in fact. If there had been more roads in Western Australia when I visited there, perhaps I would have seen more species.
Ideally, the new species shown here should be compared with their relatives, in order to illustrate what the differences are. And in the papers, such pertinent comparisons are made. However, there is some value in showing them here, because detailed photographic documentation of their features, which are interesting in themselves, is really better than a dried specimen in this group. The minute size of floral details and their delicate coloring make photographic documentation unusually valuable. Unfortunately, color documentation could not be offered in the scientific papers of those days, so I am attempting to compensate for that with the color pictures here.
Amazingly, some of the most conspicuous Stylidiaceae were among those that I described. I knew that I had discovered a new species of Levehookia when I saw it while driving: the color said Stylidiaceae, and the massive display was arresting. The species I had discovered, which I named Levenhookia pulcherrima, has by far the largest flowers of any Levenhookia. One of the Stylidium species I described, S. macranthum, has among the largest flowers in the genus—and certainly in my opinion, the most attractive. It had been seen, but relegated to another species. I sent specimens of it and relevant species to Kew for comparison to make sure that it really didn’t belong to a known species.
Tropical triggerplants. In 1977, I visited Darwin on my way to Cairns, New Caledonia, Fiji, then home again. I didn’t have any reason that would have convinced a granting agency to give me money for a visit to Darwin. I admit that I wanted to become acquainted with the tropical triggerplants. And the timing was right for the flora there. The monsoon rains come around December, when it’s quite warm there, and by July—when I planned to be there—the weather is pleasant and most plants tend to flower then. I described some tropical species of Stylidium in a 1978 paper [ PDF ]. In 1977, I took a flight from Darwin to Cairns that left at dawn. Visible from the airplane was the large Arnhem Land sandstone plateau east of Darwin, streams and rivers crossing its rough contours at curious angles, suggesting a kind of crystallinity. Apparently very little was known about plants on the plateau. Because it was sandstone and therefore acid, it would be an ideal habitat for triggerplants, I thought. Surely there would be some new ones there. But how to reach it? There were no roads to the top of the plateau, and one could get tired and lost very quickly in that rugged terrain. While in Darwin, I heard that a helicopter service had been initiated, because of exploration for uranium. That would be the only way that one could explore that untouched plateau.
Stylidium in Arnhem Land. (see pictures) So I applied to National Geographic Society for a grant to visit Darwin in 1978, and with the aid of a helicopter, explore the Arnhem Land sandstones. Applying for a grant to find new species of Stylidium may seem like an improbable thing to do, but that’s exactly what I did—and National Geographic Society funded the idea. I figured that at worst, I’d find some known species of Stylidium there and I could write something about it. I did run into a challenging obstacle. Permission to visit the Arnhem Land reserve. This area is an aboriginal research, and so I wrote the Aboriginal Council of the area for permission. No reply to either of two letters. One must remember that the Australian aborigines are not in favor of plant research, because it means removal of plants from the soil. They regard plants as an integral part of the earth, so removal of plants from the ground is immoral—as I had been told by an aborigine who saw me collecting plants in southwestern Australia in 1962. What to do? I decided to go to Darwin anyway. After arriving in Darwin, I consulted with an official in the Northern Territory government in Darwin and told him my permission problem in going up onto the Plateau. “We don’t have any police up there” was what he told me. I took that as permission of sorts—at least assurance that I wouldn’t be prosecuted. And indeed, I had no interference from anyone. I took along a Northern Territory agricultural officer, Clyde Dunlop, who provided camping supplies. I decided on three encampments, with the helicopter taking us from one to the next and then finally returning us to the Darwin airport. Telling a helicopter pilot to “put us down there” on three occasions in areas I had never seen before was a daunting experience. But looking for the first place to camp, I saw a stream with wide sandy margins. White sand! The kind of habitat that triggerplants like. I decided that we couldn’t go wrong there. And indeed, there were two new species of Stylidium in that locality, as well as some known ones. The second encampment, further east, yielded another new species. At the third encampment, there were some triggerplants, but no new ones. Three new species isn’t bad, however. At the end of the third encampment, at the appointed time, the helicopter came into view and----flew right over us without stopping! A moment of panic. Clyde Dunlop did something clever—he set fire to the dead leaves on some Pandanus trees. A perfectly safe thing to do, there was no chance of a fire spreading from one tree to another. The helicopter pilot saw the smoke and touched down, then took us on to the Darwin airport. If I had had any doubt about the merit of taking someone else along, it was erased when Clyde set fire to the Pandanus trees. I named a new species of Stylidium, found just below the scarp of the Arnhem Land sandstones, for Clyde Dunlop. I described all of these new species in a 1979 paper [ PDF ].
It’s fair to say that if Australian botanists had voted on whether or not I should have visited Australia to collect Stylidiaceae—or any of the various other things that I collected—they would have voted against me on the grounds that Australians should work on Australian plants. But nobody stopped me, and I received cooperation at every turn. Field work is an invasive act. Finding plant materials, of known species or those new to science, usually involves entering areas not frequently visited. Those who travel as tourists usually go from one city or town to another. Those of us who do field work go from one wild area to another—a demanding, sometimes difficult, kind of travel. Wilderness areas are not welcoming. They are sometimes dangerous, but the worst part about field work is uncertainty. Where should one go tomorrow and why? Setting out to find a new species is a rather preposterous activity, although in Australia at the time I was working there, the odds of it being successful were high. Setting out to find a known species that one wants for anatomical research, my usual goal, is certainly difficult. Even if one has a location along a road, where in that vicinity will one see that species; will it be common or rare? Will the area have changed so much that the species is gone? Will it be a dry year, in which the species will make no appearance at all?
After 1978, I never returned to Australia. The time there was so wonderful and productive, there was no point in more visits. I did, however, describe a few more Stylidium species [ PDF]. They were sent to me by Alan Lowrie, an amateur botanist whose enthusiasm was rather like that of Rica Erickson. He collaborated with me because I knew the apparatus for describing and puiblishing new species, and was willing to write the Latin descriptions needed for that process. My knowledge of botanical Latin is rudimentary, but the Botanical Code of Nomenclature doesn’t say that the Latin descriptions for new species must be free from mistakes in order to be valid…… Others who know more about Stylidium than I did are now studying the genus, and that is exactly as it should be. I’m surprised that in such short visits, I was able to find any new species. That I did find so many (a couple of which may be subspecies rather than species) says more about the abundant speciation in Stylidium than any special talent of mine. Interestingly, recent work in Stylidium seems to neglect infraspecific categories. But species are in various stages of origin in Stylidium, and those stages will eventually be appreciated.
In case you are wondering, there is a Stylidium named for me. Bruce Baldwin named a genus of taweeds for me in 1999, Carlquistia (Novon 9:463). I named a new species of Grubbia (there are only two other species in the family Grubbiaceae!), and I co-authored a new species and a new subspecies of Fitchia. I co-authored new species of Drosera as well as species of Stylidium with Alan Lowrie. I never discovered any new species in the United States. I’m not really a plant taxonomist in the ordinary sense. Labels are ways to mislead as often as they are ways to define. I don’t want to be labeled. Would the new species I described have been found by others if I hadn’t? Certainly. But for me, the privilege was not naming the species but focusing on evolutionary directions and characteristics.