Frailea gracillima
| Light | Bright light with a little shade from harsh midday sun; happy under grow lights |
|---|---|
| Water | Regular but light in the growing season; keep dry and cool in winter |
| Soil | Very free-draining mineral mix (see Soil and potting mix) |
| Temperature | Keep above freezing; protect from prolonged cold and damp |
| Propagation | Seed (readily set from cleistogamous flowers); occasional offsets |
| Toxicity | Non-toxic to cats and dogs |
Frailea gracillima is a diminutive South American cactus with slender, cylindrical stems clothed in fine, bristly spines. It produces pale yellow flowers that most often stay closed and self-pollinate (cleistogamous), quietly setting seed without ever fully opening. Like the rest of the genus Frailea, it is a small, obliging plant well suited to a sunny windowsill or a spot under lights.
Description
Frailea gracillima forms slender, cylindrical to somewhat elongated stems typically only a couple of centimetres thick, usually growing as a single head though older plants may occasionally offset from the base. The ribs are low and divided into small tubercles, each bearing an areole set with fine, hair-like or bristly spines that lie close against the body — soft in appearance compared with the fierce armament of larger cacti.
The flowers are pale yellow, opening (when they open at all) at the top of the stem in bright weather. As in many Frailea, most blooms are cleistogamous: they remain closed and pollinate themselves, so a solitary plant will still ripen seed. The small, papery fruits split to release fine seed. Because Frailea are notoriously variable, plants sold under this and related names can differ noticeably in stem width, spine density and colour.
Distribution and habitat
The species is native to subtropical South America, in the grassland and rocky-outcrop country of southern Brazil, Uruguay and Paraguay. Plants grow among grasses and in shallow gritty soil over rock, often partly shaded by surrounding vegetation and shrinking down during dry spells. This grassland origin is worth remembering in cultivation: these are not harsh-desert plants and appreciate a little more moisture in growth than a globular desert cactus would.
Cultivation
Frailea gracillima is an easy, quick little plant by cactus standards, and a good choice for a beginner who wants something small. Grow it in a very free-draining, mostly mineral mix in a small pot, in bright light with some shade from the fiercest midday sun to prevent scorching of the fine skin. It grows and flowers well under grow lights too.
Water regularly but lightly through the warm months, letting the mix approach dryness between waterings, then keep the plant dry and cool over winter — cold, wet compost is the main cause of loss. Because Frailea are short-lived and fast by nature, it is worth keeping a few seedlings coming along to replace older plants. See Watering and Repotting for general technique.
Propagation
Seed is the easiest and most rewarding method. Thanks to the cleistogamous flowers, even a single plant usually sets viable seed without any hand-pollination, and the fresh seed germinates quickly on a warm, damp mineral surface. Seedlings develop fast and can flower while still very young. Plants are usually single-stemmed, but any offsets that do form can be removed and rooted as a simple vegetative option. See Propagation — seed and Propagation — offsets for full walkthroughs.
Common problems
- Rot — the usual cause of death, from overwatering, a slow mix, or cold damp conditions in winter; stems soften and collapse.
- Etiolation — too little light makes the stems stretch, pale and lose their neat form.
- Pests — mealybugs (white fluff in the areoles and at the roots) and red spider mites are the common offenders; see Pests and diseases.
- Short lifespan — individual plants are naturally not long-lived, so keep raising seedlings rather than relying on one old specimen.
See also
- Frailea — the genus overview
- Soil and potting mix · Watering · Propagation — seed · Propagation — offsets · Repotting · Pests and diseases