Anigozanthos manglesii

Anigozanthos--or "Kangaroo Paws"--is a genus endemic to the southwestern corner of Australia, where a Mediterranean-type climate and nutrient-poor, acidic soils have lead to the development of a scrubby vegetation called Kwongan. Kwongan resembles the Fynbos vegetation of South Africa, which occurs under similar conditions, and the two vegetation types share quite a few of their characteristic plant families. Anigozanthos is part of the Haemodoracaeae or Bloodroot Family (no relation to the North American wildflower Sanguinaria, which is also called Bloodroot), which is represented in South Africa by the genera Wachendorfia, Dilatris and others. The Haemodoraceae have generally hairy inflorescences of flowers that are dorsiventrally symmetrical (can be divided into mirror images by only a single plane) or asymmetrical, and roots that are often brightly pigmented, and sometimes blood red.

The most common Kangaroo Paws in cultivation are A. flavidus and hybrids that incorporate A. flavidus, which are all relatively robust and vigorous plants. Anigozanthos manglesii is more finicky, requiring stronger sun to grow properly, and reportedly being very susceptible to a fungal infection called Ink Spot Disease, which fortunately doesn't seem to have made it into the botanical collections at UConn. The plants pictured here are flowering for the first time at UConn, at about two years old from seed collected near Perth, Australia. They do well in full sun in a cool greenhouse, in an acidic, peat-based soil that is allowed to surface-dry between waterings. Potted Anigozanthos plants grow and flower best when given a regular dose of dilute high-nitrogen fertilizer, but intense light and a cool winter growth period are probably the more critical requirements for success.

Talk in Philly

Ferocactus viridescens var. viridescens, Dudleya edulis.

This Sunday I'm giving a talk at the Philadelphia Cactus and Succulent Society, titled "Succulents of Southern California." The presentation will include elements from my blog posts on the subject earlier this year, but greatly expanded.

Tylecodon opelii

There's big excitement (for me, at least) in the latest issue of the Cactus and Succulent Journal: Ernst van Jaarsveld of Kirstenbosch and Steve Hammer of the Sphaeroid Institute have named a new species of Tylecodon in my honor. Tylecodon opelii is a winter-growing geophyte, with dark marble-sized and marble-shaped leaves, endemic to fields of broken quartz in the northern Knersvlakte in South Africa's Western Cape.

Tylecodon opelii in cultivation, late winter.

The new Tylecodon is set apart from its relatives by spheroid leaves that are dark green to nearly black and almost glabrous, with just a few fine hairs. It's probably most closely related to T. occultans, though that species has more flattened leaves and less elongated tubers.

The quartz field habitat of Tylecodon opelii.

The corner of the Knersvlakte where I first ran into what is now T. opelii back in the austral winter of 2000 is loaded with little geophytes and succulents. The white quartz covering the ground reflects and disperses sunlight, creating a microhabitat where dwarf vegetation can thrive. In places without the quartz, darker soils absorb light and heat up to the point where small plants at ground level get cooked. I have fond memories of hiking through this strange landscape, scanning the ground for interesting plants, finding round black leaves coming up between the pebbles and thinking: "Hmm, what Tylecodon is this? I've never seen it before." I'm very grateful that it wound up getting named after me, years later.

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van Jaarsveld, E.J. and S. Hammer 2011. Tylecodon opelii, a new obligatory quartz-gravel species from the Northern Knersvlakte (Western Cape, South Africa). Cactus and Succulent Journal (US) 83: 140-145.

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There's a short blurb on Tylecodon opelii on the University of Connecticut website, too.

Welwitschia seeds!

The Welwitschia mirabilis plants at UConn produced abundant fully-formed cones for the first time, this past summer. On warm afternoons in midsummer, the mature female cones produced "pollination drops," or droplets of nectar at the end of hair-like extensions of the ovules. The male cones have nectaries, as well, which probably attract insect pollinators in the wild in Namibia.

I placed pollen from the males into the pollination drops of female cones for several days running back in July, and two months later the seeds are starting to mature. Some of the seeds are very light and thin, and are probably duds, but quite a few look like viable Welwitschia seed. I may plant a few now to see what happens, though it probably isn't the best time of year.

Female cones with pollination drops, back in midsummer.

Succulents of Coastal Southern California 2: Cacti etc.

Ferocactus viridescens var. viridescens overlooking the Pacific at Torrey Pines State Reserve.

Apart from the Crassulaceae (stonecrop family), the Cactaceae (cactus family) is probably the group of succulent plants that is most prominent in the flora of the San Diego area. The most frequently encountered cacti are Opuntia and Cylindropuntia species, the prickly pears and chollas. There are several species of each genus in the area, ready to stick unwary hikers with barbed spines and glochids. Some, like Opuntia littoralis, form impressive spiky clumps.

Opuntia littoralis among spring wildflowers at Torrey Pines.

Ferocactus viridescens looks a little out of place in the chaparral of the coastal regions; the genus is much more widespread in true desert, inland. This small barrel cactus grows mostly on open gravelly slopes, though I spotted a few plants under the scrubby vegetation that dominates the area. Ferocactus viridescens seems to be relatively rare, and getting more so: a botanist told me about a large population in downtown San Diego that persisted for many years on a steep slope amid the parking lots and hotel complexes, which was just recently wiped out by development.

The cactus genera Mammillaria and Bergerocactus are also represented in coastal SoCal, though I’ve never spotted them in the wild. The local climate is almost entirely winter-rainfall, and it seems like the native cacti in the area grow and flower mainly in the cooler part of spring. I suspect that they would do most of their growing in the summer sun if cultivated in a greenhouse in the Northeast, but it would be worth experimenting with keeping them active in the winter.

Yucca shidigera at Torrey Pines.

Yucca and related genera Hesperoyucca and Agave (family Agavaceae) are also encountered in the patchy remnants of the wilds of greater San Diego. Yucca schidigera, Spanish Dagger, is widespread in the Sonoran and Mohave deserts, as well as the chaparral. It branches from the base and grows into a good-sized shrub, often taller than a person.

Marah macrocarpus in a weedy hedgerow on the agricultural outskirts of Vista, Ca.

Marah macrocarpus, California Manroot, is a caudiciform plant in the squash family (Cucurbitaceae). Marah produces scrambling, leafy vines in the winter and spring, but the interesting part of the plant, from the perspective of the succulent-plant fan, is the massive tuber. In the wild, the tuber stays unseen deep underground, but caudiciform growers can raise their Manroots partially above ground for viewing. So to speak.

Mesembryanthemum crystallinum on the beach. Invasive, but pretty.

Finally, the beaches and freeway medians of Southern California are host to a wide variety of ice plants (family Aizoaceae). Most of these are introduced from South Africa, but at least one species—Carpobrotus aequilaterus (Sour Fig)—is most likely native. Some of the exotic ice plants, including Mesembryanthemum and other species of Carpobrotus, have become invasive weeds, sometimes even encountered in wild areas.

The alien Carpobrotus edulis, grown as a groundcover in Vista, California. The native C. aequilaterus is similar, but with violet flowers.