Yavia cryptocarpa is the only species of the recently (2001) discovered genus Yavia. The genus is named after Argentina’s department Yavi, Jujuy Province, where the plant is endemic to sparsely vegetated rocky slopes. The specific epithet cryptocarpa refers to the plant being a cryptocarp, which means that the fruits are formed inside the plant’s body, and are only visible when the plant shrinks during periods of drought. The name ‘cryptocarpa’ means ‘hidden fruit’.

In its habitat, vegetation is scarce, with only some well-spaced bushes. Temporary grasses can be found for some weeks after the rains, which fall between December and March, but it is also possible to have a little rainfall from October to April.

The small stems of Yavia are single, more rarely with two or more heads, and are normally just at the level of the soil surface or even below, sunk in crevices. Some are covered by small pebbles. The stems are small; a specimen of 25mm diameter would make an extraordinarily fat and old plant. They have a flat top, with a woolly depression in the centre. This superior disk is the only visible part of the plant and the only part that receives the sun’s rays. The areoles are arranged in several lines that are not really ribs, just small undulations and cannot really be described as tubercles. The spines are small, 0.3–0.7mm long, and barely visible without the aid of a magnifying glass. The lateral part of the stem is almost cylindrical and is rugose. This rugosity corresponds to previous epidermal tissue of the superior disk, which over the years comes to the side, with the spines attached although decrepit, more or less destroyed. It is thought that these ‘wrinkles’ correspond to one year’s growth and more than twenty have been counted on some plants. Cultivated plants change dramatically in their aspect. The roots are conical, succulent, and are a continuation of the underground stem.

0522 Fig. 1

Fig.1

My plant in the photos (Fig. 1) was a graft and it was a plant the BCSS introduced into cultivation in the UK from their original propagations. They are tuberous-rooted in nature so then need a deeper pot. Evidently it is self-sterile as my plant produced fruit embedded in the crown (Fig. 2) but they had no seed in them. Alas the scion then shrivelled up on the graft even though the stock remained healthy. So, I now need to find a replacement.

0522 Fig. 2

Fig.2

Dave Whiteley (with extra text by Al Laius)

 

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