#vitaceae

Cyphostemma juttae

Cyphostemma is a genus in the Vitaceae, or Grape Family, well known for how enormous their swollen bases can get. This one is Cyphostemma juttae, from Namibia, and its large succulent leaves are present from spring to fall, during its growing season, but they are shed during the winter. The tiny flowers are not showy, but they are followed by round red fruits that look like grapes, but they are poisonous. A wonderful botanical curiosity.

Grechetto

Thrush

Now it’s a friend

Of grapes

ヤブガラシ

これでブドウの

仲間なり

Causonis Japonica. Vitaceae.

Ungleiches Paar (detail)

by Lucas Cranach d. Ä. (Bambergian, 1472 – 1553) oil on lime panel, 1532

An unfamiliar grape I found at a cemetery. Mustang grapes (Vitis mustangensis) dominate this region, but they are very obviously different; larger in every way, with bigger clusters of fruit, and the backs of the leaves are white. The black grapes are also very tart and sting your mouth thanks to high quantities of oxalates. In contrast, the few edible-looking grapes on this vine were red and glaucous and quite mild and sweet, even though I don't think they were fully ripe. This offers us some constraints: extremely heat- and drought resistant, back of leaf not tomentose and same color as the front, smaller, palatable fruit, one large seed per fruit (collected three, 5-6mm long), grows on alkaline soil. There were other things I should have paid attention to, like the color of the bark and exact dimensions, and I should have collected a leaf for closer inspection of any small hairs, but I didn't.

I am very much not a Vitis expert, and admittedly haven't been paying much attention to them in general. There are a number of species in the area, including some Edwards Plateau endemics. The interesting thing about grapes, in contrast to the vast majority of plants, is that viticulture has neurotically picked over and assessed every North American species and natural hybrid for agricultural potential, no matter how obscure. You can find incredibly detailed charts for distinguishing one named cultivar from another. Theoretically this should make identification rather easy, but I'm still not certain. The five-lobed leaves suggest aestivalis, but the soil does not. Rotundifolia also excluded by alkalinity as well as the large size of its fruit. Berlandieri aka cinerea var. helleri seems like the most likely option, though I cannot find any indication it assumes a 5 lobed form. I suppose I can't eliminate Vitis monticola, but the same issue applies. It could be a hybrid with mustangensis, which does have an elaborately lobed form. It could be some manmade escapee. I'll go back at some point and take a better look.