Frailea pygmaea
| Light | Bright light with shade from harsh midday sun; a little more shade than most desert cacti |
|---|---|
| Water | Moderate in growth; allow to dry between waterings; keep dry through winter |
| Soil | Fast-draining but slightly humus-rich mineral mix (see Soil and potting mix) |
| Temperature | Keep above freezing; USDA zones 9b–11 |
| Propagation | Seed (primary); occasional division of clumps |
| Toxicity | Non-toxic to cats and dogs |
Frailea pygmaea is one of the smallest of all cacti, a diminutive clustering plant from the grasslands of Uruguay and neighbouring Argentina. Each thumbnail-sized stem is barely a couple of centimetres across, yet mature plants form tidy little mounds that produce disproportionately cheerful yellow flowers. Like others in the genus Frailea, it is a plant for growers who enjoy the miniature end of the hobby.
Description
Frailea pygmaea forms a small, flattened-globular stem usually only 1.5–3 cm in diameter, offsetting in time to build a low cluster of heads. The body is greyish- to olive-green, sometimes flushed reddish in strong light, and divided into many low, tuberculate ribs. The spines are tiny, comb-like (pectinate) and pressed close against the body, so the plant feels more bristly than sharp.
Flowers are yellow and open at the crown, often looking almost too large for the plant that bears them. As with the rest of the genus, the flowers frequently do not open fully, and the plant is strongly cleistogamous — it will set viable seed inside unopened buds, so a solitary plant can still fill its little seed pods.
Distribution and habitat
The species grows in southern Brazil, Uruguay and parts of northern Argentina, where it is a plant of open grassland and rocky outcrops rather than true desert. In habitat the tiny stems nestle among grasses, mosses and low vegetation that shade the soil and shelter them from the fiercest sun, often growing in shallow, gritty pockets over rock.
Because these are seasonally moist grasslands, Frailea species are accustomed to more regular moisture in the growing season than many desert cacti — a useful thing to remember in cultivation.
Cultivation
Frailea pygmaea is an easy and quick little cactus by the standards of the family, well suited to a windowsill or a small pot in the collection. Grow it in a free-draining mix that holds a touch more organic matter than a strict desert blend, and give it bright light with protection from scorching midday sun — too much fierce sun can bronze or mark the delicate body.
Water fairly generously through the warm months, always letting the mix approach dryness between waterings, then keep the plant dry and cool over winter to rest it and prevent rot. These are naturally short-lived, fast plants, so it is worth keeping seed coming along to replace older clumps. See Watering and Repotting for general technique.
Propagation
Seed is by far the main method, and Frailea makes it easy: thanks to its cleistogamous flowers, even a single plant will usually produce pods of viable seed without a partner. Sow on a warm, gritty surface kept humid and the seedlings appear readily and grow quickly. Established clumps can also be divided, and rooted offsets will establish without much fuss. See Propagation — seed and Propagation — offsets for full walkthroughs.
Common problems
- Rot — the usual cause of loss, from overwatering, a stagnant mix or cold damp conditions; the small stems soften and collapse quickly.
- Etiolation — too little light makes the body pale and stretch upward, spoiling the neat flattened shape.
- Short lifespan — individual heads are naturally not very long-lived, so plants can fade with age; keep raising seedlings to maintain a clump.
- Pests — mealybugs (white fluff in the crevices) and red spider mites are the usual culprits.
See also
- Frailea — the genus overview
- Soil and potting mix · Watering · Propagation — seed · Propagation — offsets · Repotting