Fenestraria
Fenestraria is a small southern African genus of clump-forming succulents in the ice-plant family Aizoaceae, famous for their upright, club-shaped leaves whose flattened, translucent tips act as tiny "windows". In habitat the plants sit almost buried in sand with only these glassy tops exposed, and the resemblance of a tight cluster of leaves to a row of little digits has earned them the affectionate common name baby toes.
The genus is very small — often treated as a single variable species, Fenestraria rhopalophylla, with the widely grown golden-flowered plants placed as subspecies aurantiaca. Because of this, most of what follows applies to the genus as a whole.
Description
Fenestraria plants form low, spreading mats of soft, finger-like leaves. Each leaf is roughly cylindrical to club-shaped, pale grey-green, and topped by a flattened or slightly domed transparent panel — the "window" (Latin fenestra). This window is the key to the plant's biology: in the wild the leaves grow mostly below the soil surface, and light enters through the exposed tips and passes down into the photosynthetic tissue within, a strategy shared with other "window-leaved" succulents such as some Haworthia and Lithops.
Flowers are daisy-like, appearing singly on short stalks and often nearly as wide as a leaf cluster. They open in the cooler part of the year (autumn into winter under cultivation) in shades of white to warm golden-yellow, depending on the form.
Distribution
The genus is restricted to the coastal deserts of southern Namibia and neighbouring northwestern South Africa. There the plants grow in loose, sandy soils within reach of frequent coastal fog, which supplies much of their moisture. This foggy, winter-rainfall origin shapes their care: they are adapted to cool, damp winters and hot, dry summers — roughly the reverse of many summer-growing cacti.
Notable species
- Fenestraria rhopalophylla — the type and, in most treatments, the only species; a white-flowered plant of the coastal sands.
- Fenestraria rhopalophylla subsp. aurantiaca — the golden-yellow-flowered form seen in most collections, and the plant usually sold simply as "baby toes".
Older names such as Fenestraria aurantiaca are today generally regarded as synonyms or subspecies of F. rhopalophylla rather than as distinct species.
Cultivation
Fenestraria has a reputation for being tricky, but the difficulty is almost entirely about water and light rather than anything exotic. Grow plants in a very gritty, sharply draining mineral mix in a pot deep enough for the surprisingly long roots. Give bright light — enough sun to keep the leaves short and firm; in too little light the leaves stretch, soften and split, and the neat "toes" become loose and floppy.
Watering is the crux. These are cool-season growers, so water lightly in autumn, winter and spring when the plant is active, always letting the mix dry between drinks, and keep them nearly dry through the heat of summer when they rest. The commonest way to lose a Fenestraria is a split, rotting leaf caused by a generous watering during dormancy or in soggy soil. Err on the side of underwatering; a slightly shrivelled plant recovers, a waterlogged one usually does not. See Watering and Repotting for general technique.
Protect plants from frost — treat them as tender and keep them above freezing.
In cultivation
Baby toes are popular novelty succulents, sold both as small potted plants and as seed. There are no elaborate named cultivar groups as with some genera; interest centres instead on flower colour (the golden aurantiaca forms versus paler whites) and on growing a tight, healthy cluster of plump, un-stretched leaves. They combine well in shallow arrangements with other winter-growing mesembs, provided everything shares the same lean soil and careful watering regime.
Propagation
Fresh seed is a reliable route and germinates readily on a mineral surface kept lightly moist and warm; see Propagation - seed. Established clumps can also be lifted and divided into rooted pieces, much like offsets — see Propagation - offsets — though divisions resent being kept too wet while they re-root.
Common problems
- Split or rotting leaves — the classic Fenestraria failure, caused by watering during dormancy, an over-rich or slow-draining mix, or simply too much water at once; the leaf bursts and turns to mush.
- Etiolation — too little light makes leaves elongate and flop, and clusters lose their tight, toe-like form.
- Pests — mealybugs (white fluff between the leaves and at the roots) and the occasional fungus gnat in soil kept too damp.
See also
- Aizoaceae — the ice-plant family
- Other window-leaved and mesemb succulents: Haworthia
- Soil and potting mix · Watering · Repotting · Propagation - seed · Propagation - offsets · Pests and diseases