Xerophyta retinervis

Xerophyta retinervis, or “Black Stick Lily,” is a flowering plant from the high-altitude interior of eastern South Africa, with tufts of coarse leaves emerging from a clump of fat stems with a fibrous coat. The stems are often charred by fires in the veld, giving rise to the first part of Xerophyta’s common name. The “lily” part of the name comes from the large cobalt violet flowers that seem to emerge from the stems and open overnight, and always catch me by surprise when they appear in spring. I have hardly ever caught the early stages of flower development, but it is less than a week between no visible flower buds at all and full bloom.

Xerophyta is part of the family Velloziaceae, which is a small, Southern Hemisphere group of monocots (plants like palms or grasses that typically have parallel leaf venation and a single seedling leaf). The Velloziaceae are related to Pandanus, the screwpines, a genus of tropical swamp and coastal trees.

Xerophyta retinervis is poikilohydric, like Myrothamnus, which I wrote about in a previous entry.  That is, it is a “resurrection plant,” which can become completely dehydrated, then soak up water and start growing again when conditions are favorable. In the greenhouse I’ve seen this happen once, accidentally: the leaves curled up and turned yellow, and the plant looked like it was finished, but it perked up again and looked fine a few days after watering.

The desiccation and resurrection process in Xerophyta has been the subject of a certain amount of research, in part because of interest in improving the drought tolerance of crop plants, and it turns out that the leaves actually break down all of their chlorophyll when drying, then rapidly synthesize new photosynthetic pigments when water is available again. In cultivation, it’s probably safest not to test this remarkable ability too much, and keep the plants well-watered during the summer growing period, and barely moist enough to keep the plant from dehydrating in winter. No matter how I treat Xerophyta, it does tend to drop a lot of its foliage in the cooler months.

 References:

Tuba, Z. et al. 1994. Planta 192: 414-420.

Clark, W.D. et al. 1993. Annals of the Missouri Botanic Garden 80: 987-998. 

17th Eastern Cactus and Succulent Conference

The Eastern Cactus and Succulent Conference is coming up next weekend, April 13-15, in Waterbury, Connecticut. It will be an exciting and informative time, but also extremely busy because a) I'm president of the club that is hosting the conference, and b) I'm giving two talks. Maybe I can sneak over to the indoor water park at the conference center to take a break at some point.

Diplosoma luckhoffii, a mesemb in the Mitrophyllum Group.

Talk #1, Saturday afternoon, will be "Other Mesembs." Anyone attending a cactus conference will know at least something about Lithops, the living stones, but there are about 120 (depending on your taxonomy) other genera of succulent plants in the family Aizoaceae. In this presentation I'll try to provide an overview of the succulent Aizoaceae, or mesembs, some familiar but many likely to be obscure to all but the most dedicated specialists.

Pelargonium longifolia, a tuberous species in section Hoarea.

"Succulent Pelargonium" is the topic for my Sunday morning presentation. Pelargoniums suffer form an even more extreme form of the sort of selective fame that afflicts mesembs: everyone with event the slightest knowledge of gardening knows the windowsill geraniums, which are actually hybrid pellies, but there is a whole world of succulent, desert-dwelling Pelargonium species that are little known and rarely cultivated.

I hope to see some of you at the conference! Keep in mind that, while the conference talks and events will be restricted to those who register, there is a succulent plant show and sale that is free and open to anyone, running Saturday and Sunday at the same location in Waterbury.

Caiophora chuquitensis

The Caiophora chuquitensis plant at UConn is starting to produce salmon-orange flowers, about 4 cm in diameter. The blooms are nice, if not as extravagant as the flowers on some other members of the family Loasaceae. The plant reached maturity at only a year old from seed, which leads me to suspect that, like some other plants in the family that I've tried to grow, it is naturally short lived. I'll give it some extra fertilizer and try to keep it going for as long as possible.

Closeup of Caiophora chuquitensis leaf, showing trichomes.

Apart from intricately beautiful flowers, the family Loasaceae is known for its wicked stinging hairs. I've brushed up against the Caiophora once or twice, and it's not as bad as a bee sting, but more painful than stinging nettle. As with stinging nettle, the trichomes in the Loasaceae sometimes have cell walls impregnated with silica (glass, more or less), which break on contact and act like a hypodermic needle to inject toxins.

Maple Sugaring Wrap up

This year's maple syrup harvest; from left to right: week1-2, week 3, week 4, Red Maple syrup from week 1-2.

The sugaring season is officially over; I did my final boil on Monday and pulled out the taps. The last batch was quite dark, with quite a lot of sugar sand (a silty, bitter-tasting precipitate that needs to be filtered out). The local commercial sugar shack, River's Edge Sugar House, shut down its operations this past weekend. They had a relatively short, low-productivity season too, but made enough syrup to make the effort worthwhile. Apparently, they have vacuum systems on the sap lines in some of their larger sugarbushes, which enable them to harvest decent quantities of sap even when the weather is less than ideal. Vacuum or no, the weather forecast for the next 10 days doesn't even predict any frost, and the tree buds are swelling, making any further sugaring impossible.

My experiment with tapping a Red Maple (Acer rubrum) was kind of a flop; I can see why people generally don't bother with them. Sap flows were low compared to the Sugar Maples, and just about stopped towards the end on February, two weeks before the Sugar Maples quit. The final results for the Red Maple boil were 12 cups of sap to 0.25 cups of syrup, or about 50:1 (Sugar Maples yield something closer to a 40:1 sap to syrup ratio, though some sap runs were a little more watery this year).

It's time to start thinking about this summer's outdoor, vaguely-self-sufficiency-related project: beekeeping. I've acquired and assembled most of the hardware, taken the Eastern Connecticut Beekeeper's Association bee class, and my girlfriend has a couple of packages of bees on order from Anarchy Apiaries. The bees should arrive in early May, and I'll have some updates then.

Signs of Spring

The weather the past few weeks has been pretty poor for sap flow (mostly too warm at night), and even the good days, with nights in the teens and sunny days with temperatures well above freezing, have produced mediocre sap runs. There has been nothing even approaching the one-gallon-per-tap days that were pretty frequent last year. I've gotten a few cups of maple syrup by boiling down what little the trees have produced, but it's going to be a crumby year for sugaring.

The Skunk Cabbage (Symplocarpus foetidus) has been up and blooming for a while now, in low soggy places in the neighborhood woods. Symplocarpus is always the first native plant to show signs of activity in late winter; the inflorescences famously produce their own internal heat, and sometimes melt their way up through a fair amount of ice and snow. It's a member of the family Araceae, like the Titan Arum, another "warm-blooded" plant. This photo was taken on leap day, when we had a little slushy snow.