Friday, November 7, 2008

Talk in Philadelphia

Eriospermum armianum (Ruscaceae), from west of Springbok, Northern Cape, South Africa. Single leaf with club-shaped outgrowths called enations arising from its surface.

I'm going to be giving a presentation on "Winter Growing Geophytes of South Africa" to the Philadelphia Cactus and Succulent Society this Sunday, November 9. The meeting will be from 11-3:00 at the Fairmount Park greenhouses, and my talk itself will likely take an hour or so, starting around 1:00. It should be fun; the PCSS is one of the largest and most active groups of its kind in the country; I was a little overwhelmed by the size and enthusiasm of the audience when I gave a talk on Conophytum in Philly last year.

The presentation will be a basic introduction to what is a huge subject; a lowball estimate of the number of winter growing tuber and bulb species in South Africa, from the Color Encyclopedia of Cape Bulbs, is around 1500. I'll talk about cultivation, the ecology of the plants in the field, and a little bit about morphology and anatomy, while showing slides of a somewhat scattershot sampling of Cape bulb diversity. The genus Eriospermum will be overrepresented, because I like eriospermums and have a bunch of photos of them, but I'll touch on the usual suspects too, like the Amaryllidaceae (Amaryllis family) and Hyacinthaceae (Hyacinth family), as well as some possibly unfamiliar dicot geophytes, like the tuberous Pelargonium species (Geraniaceae - Geranium family).

Friday, September 26, 2008

Century Plant in Bloom

We have a relatively rare botanical event going on in the University of Connecticut greenhouses right now: an Agave, or Century Plant, is in bloom. This plant is probably Agave filifera ssp. schidigera, a native of Mexico, but I'm not entirely certain of the identification. The plant has been in the greenhouse at least since the staff started keeping careful records in 1985, and its origins are uncertain. It's got an impressive inflorescence, at any rate, about 12 feet high, with hundreds of greenish flowers opening sequentially from the bottom to the top. The flowers literally drip nectar, and have an odd vegetable smell, sort of like steamed artichokes.

This is the first time this plant has bloomed in its 23 plus years, but "Century Plant" is clearly an exaggeration. Agave plants are monocarpic, which means that the plants cease growth and die shortly after flowering and setting seed. Many Agave species produce vegetative offsets or runners, though, so only the individual rosette that sends up an inflorescence croaks, while a ring of clones around it survive. Our Agave filifera hasn't produced any offsets yet, so it may be gone for good after putting on its show. I'm attempting to self-pollinate it, but it isn't always possible to set seeds with only one plant.

Century Plant blooms are fairly rare in northern greenhouses: at UConn, we keep about 20 agaves, and have had only this single flowering in the past 10 years. In warmer, drier parts of the country, Century Plants--especially Agave americana--are grown as bedding plants, and flowerings are commonplace in suburban gardens and highway plantings.

Tuesday, September 23, 2008

Conophytum minusculum: The Minuscule Cone Plant

Conophytum minusculum in September, still in summer mode apart from the flowers. These plants are an informal cultivar named “Roseum” with particularly intense floral coloration, derived from material collected by plant explorer Frank Horwood.


Mid-September is the peak season for Conophytum flowers, and for a brief interlude my collection looks something like a very small version of the poppy fields in Oz. Cono flowers tend to be incongruously gaudy compared to the compact, often camouflaged vegetative portions of the plants. The flower/leaf mismatch is particularly extreme in Conophytum minusculum, which has succulent leaf pairs the size of match heads, which sport violet to dayglow pink flowers easily five times as large.

Conophytum minusculum hails from the southwestern parts of the range of the genus in South Africa, which means it is adapted to a relatively mild Mediterranean climate, rather than hard desert. The plants grow in crevices and among mosses and lichens on sandstone outcrops, in a scrubby vegetation type peculiar to the Cape region called fynbos. Fynbos occurs on sites with poor, acidic soil and winter rainfall. Fynbos is subject to fires every decade or two, though it seems unlikely that the rocky, barren niches that Conophytum plants favor ever burn directly.

Conophytum minusculum is a definite cool-season grower, and tends to be even more strict about seasonality that other conos. Although the plants flower in the early autumn, the new leaves often don’t take up water and emerge from their summer sheaths until it really gets cold and dreary in November or December. In cultivation, I water the plants more than usual for winter growing South African succulents, enough to keep the soil evenly moist from flowering, through the fall and winter, up until the point where the leaves yellow and dry up for the summer dormancy in April. The plants need as much sun as possible in winter. During the warmer months, I keep my C. minusculum pots in partial shade, and do not water except for a light misting every few days. Summer misting should be just enough to barely moisten the surface layers of soil, which prevents possible losses from sunburn.

The soils where C. minusculum grows in the wild are particularly thin and low in mineral nutrients, and under glass the plants do well in shallow pots, with a gritty, impoverished soil mix. If I were really on top of things, I’d water them with rainwater, though the tap water here in eastern Connecticut seems to be sufficiently clean and low in salts. The plants are well suited to cultivation in New England; famous succulent growers in the Southwest have trouble getting C. minusculum and its relatives to thrive, because of their relatively hot, dry weather and hard, salty water. But the plants thrive here in Swamp Yankee country.

Conophytum minusculum is mostly propagated by cuttings, which establish easily in fall or winter. Seed is hardly ever available: the flowers aren’t easy to pollinate, and even successful pollination tends to result in only small numbers of seeds.

Monday, August 18, 2008

Eastern Cactus Conference Mop-up

Ernst van Jaarsveld and the gang judge the Gasteria class (Ernst, literally, wrote the book on the genus).

First off, I have to thank everyone at the Cactus and Succulent Society of Massachusetts for organizing such a superb convention. They really outdid themselves, and I think everyone who attended had a wonderful time. There was one scheduling SNAFU that I noticed, but it seemed to be strictly the hotel's fault, and in any case all the affected events were accommodated the next day, with a pizza lunch thrown in to compensate for the delay.

The quality of plants at the show was outstanding, as was the quality of the plants for sale from the vendors. Somehow, my pot of Burger's Onions (pictured in the header of this blog) managed to take best in division for the succulents other than cacti, which was gratifying. The CSSM club table offered a wide selection of mesembs and haworthias, in perfect shape after being shipped in from the Sphaeroid Institute in California. The banquet was, well, hotel banquet food, but the company was excellent. The auction, which ran until nearly midnight after the banquet, was pretty spirited for a recession year, and it was nice to see some of the more obscure succulents, like Conophytum, inspire bidding wars.

For me, at least, it is the lectures that really make the convention. I missed out on a couple of talks because of conflicts: I regret not seeing Dennis Cathcart's presentation on succulent bromeliads, a subject on which I could use a refresher course, and I hear that Jerry Barad gave a fascinating talk on the early history of the New York Cactus and Succulent Society. I did catch and enjoy Fred Kattermann's talk about Chilean cacti, and two presentations by Panayoti Kelaidis about cold hardy succulents, one dealing with the cultivation of native plants in the arid Southwest, and the other a travelogue of Panayoti's botanical explorations at high altitude in Southern Africa. Mark Dimmitt's slide show about Northern Mexico included some spectacular photography, as well as a lot of solid information about the ecology of the various drought-adapted vegetation types in that part of the world.

Steve Hammer gave two talks. The first, "Snow White and the Seven Hundred Dwarfs," was an overview of the more compact mesembs, including a number of small--in terms of number of species and plant size--genera like Psammophora (which has sticky leaves that catch a protective coating of sand) that usually don't get much love from growers. At his second talk, Steve spoke about hybrid Haworthia, the economics of horticultural fads, and what he thinks of as the futility of keeping track of the pedigree of cultivars. All the while he passed around examples from his haw collection, many of which could no doubt finance a mortgage payment if sacrificed to EBay. As far as I know, all the plants made it back to lectern by the end of the talk, without a leaf missing. Steve's talks are rather similar to his writing: wide ranging but coherent, with a literary quality that is sometimes nearly Twainian, and peppered with allusions to everything from the King James Bible to Brittney Spears.

The most fascinating presentations of the weekend, for me at least, came from Ernst van Jaarsveld, curator of the conservatory at Kirstenbosch Botanical Garden, who was flown in from South Africa by a coalition of American cactus clubs; he was off to Denver after the Eastern Convention. Other speakers may have been more eloquent--Ernst's first language is Afrikaans--or had prettier photos or fancier PowerPoint presentations, but at Ernst's talks, more than the others, I felt that I was learning about things in the natural world that I wasn't aware of before, and in fact hadn't remotely suspected. There is, for example, a succulent grass that grows around Alexander Bay at the border between South Africa and Namibia. Dregeochloa pumila looks like a Peperomia or some such poking out of the sand, but it's in the same family as your lawn. I hardly would have believed it before seeing the images. And no, Dregeochloa is not in cultivation, though Kirstenbosch is trying to acquire material. Also riveting for me was Ernst's accounts of a trip to Dolphin Head in Namibia to see Jensenobotrya lossowiana, Jensen's Grape, at one of its two known localities. I had known the basics of the Jensenobotrya story before, but it was something else entirely to hear a first hand account of its nearly inaccessible habitat on a spire of rock jutting into the icy South Atlantic, surrounded to the east by a sea of shifting dunes, and to see new images of individual plants, seemingly unchanged from their appearance in black and white photographs from 30 years ago. Fortunately for those who couldn't attend the convention, Ernst has written about Jensenobotrya online, at http://www.plantzafrica.com/planthij/jensenloss.htm.

My own talks, one on Conophytum and one on why the names of plants sometimes change in response to new information from modern evolutionary biology, seemed to go over reasonably well. A solid majority of the audience had their eyes propped open whenever I checked, anyway.

Steve Hammer, with a very expensive lump of vegetable matter.

Saturday, August 16, 2008

16th Eastern Cactus Conference - First Day

The Cactus Con is going swimmingly, so far. Yesterday was mostly taken up by settling in and dinner at a fair-to-middling Chinese restaurant called Hong Kong ("Hong & Kong" on the menu), but there were some presentations, too. Chris Allen and Glen Lord gave a demonstration on succulent bonsai, with Chris describing cultivation techniques (from the point of view of a Conophytum grower, he waters and fertilizes the bejeezus out of his caudiciforms, at least in summer, though you can't argue with his results). Meanwhile, Glen, a grower at Bonsai West, talked about how to shear the resulting masses of vegetation.

Then, Fred Kattermann of New Jersey talked about Copiapoa, a genus of globular cacti from the extreme deserts on the coast of Chile. Fred had some really amazing photographs of the little guys clinging to rocks, sinking into clay and leaning out of the sun in habitat. Finally, Matt Mattus of the CSSM gave a charming presentation on a typical yearly cycle of growing Oxalis, Nerine, Clivia and other South African geophytes in his greenhouse.

Here are some photos from the show setup, which I should get back to...

Glen Lord, Steve Hammer, Ernst van Jaarsveld and Abby Rorer discuss plants for the show.

Show setup in progress. Judging theoretically starts in one hour.


Good stuff for sale at the CSSM table, courtesy of the Sphaeroid Institute.


The sale area.


Some of the plants assembled for the auction tonight.