Haworthia truncata
| Light | Bright, filtered light; a few hours of gentle sun, shade from harsh midday sun |
|---|---|
| Water | Moderately in growth; keep drier in the heat of summer and through winter dormancy |
| Soil | Gritty, fast-draining mineral mix (see Soil and potting mix) |
| Temperature | Keep above freezing; USDA zones 10–11 |
| Propagation | Leaf cuttings, division of offsets, and seed |
| Toxicity | Non-toxic to cats and dogs |
Haworthia truncata is a small, slow-growing succulent from the Little Karoo of South Africa, instantly recognisable for its leaves arranged in a flat, two-ranked fan. Each leaf ends in an abruptly flattened, translucent "window" that looks as though it has been sliced off with a knife — a feature that has earned the plant its common name, horse's teeth. In habitat the leaf tips sit flush with the soil surface, the plant living almost entirely buried with only these glassy tops exposed to the light.
Description
Haworthia truncata is a compact, clump-forming succulent whose leaves — unusually for a haworthia — are not held in a rosette: they grow in a single flattened plane, stacked in two opposing rows (a distichous arrangement) to form a fan. The individual leaves are thick, upright and squared off at the top, where the surface is smooth and translucent. These clear leaf tips are "windows" — patches of near-transparent tissue that let light down into the buried body of the leaf, a form of fenestration shared with several other window-leaved Haworthia and related genera.
The upper, exposed surfaces are typically rough or minutely warted, and can range from dull grey-green to dark brownish tones depending on light and clone. In the wild only these truncated tops are visible at ground level, so the plant is easily overlooked among the surrounding stones and grit. Small, tubular white flowers with fine brownish stripes are carried on a slender stalk, but the plant is grown almost entirely for its striking foliage rather than its bloom.
Distribution and habitat
The species is endemic to the Little Karoo (Klein Karoo) region of the Western Cape, South Africa, where it grows in arid, rocky ground under a mostly dry climate. Plants withdraw into the soil, sitting with the windowed leaf tips at or just below the surface among gravel and low vegetation. This buried, "contractile" growth habit protects the bulk of the leaves from intense sun, heat and grazing, while the translucent windows admit enough light for photosynthesis to continue underground.
Cultivation
Haworthia truncata is an undemanding and rewarding plant for the windowsill or a bright shelf, and it tolerates less intense light than most cacti. Give it bright, filtered light — an east- or shaded south-facing position is ideal — with protection from scorching midday sun, which can mark the exposed leaf tops. Unlike its habit in the wild, in cultivation it is usually grown with the leaves sitting above the soil so the fan can be admired.
Plant it in a gritty, free-draining mix that is mostly mineral, and water moderately while the plant is in active growth, allowing the soil to dry out between waterings. Ease off during the hottest part of summer and through winter, when growth slows. Being naturally slow, it is happy in a snug pot and appreciates only occasional repotting. See Watering for general technique.
Propagation
H. truncata is unusually easy to propagate vegetatively for a haworthia. It can be increased from leaf cuttings: a healthy leaf detached cleanly at the base and left to callus will often sprout new plantlets from its base. Established clumps also produce offsets that can be separated during repotting — see Propagation — offsets and Propagation — cuttings.
It can be grown from seed as well, though seed-raised plants are slow and, because the species is variable and readily hybridised, seedlings may differ from the parent. See Propagation — seed for a full walkthrough.
Cultivars
Haworthia truncata is popular with collectors and has been selected and hybridised extensively, particularly in Japan. Selections are chosen for the size and clarity of the leaf windows, the surface texture, leaf count and overall symmetry of the fan. It also crosses readily with Haworthia maughanii — now usually treated as a variety of the same species (H. truncata var. maughanii), whose leaves form a rounded, spiral cluster rather than a flat fan — and such crosses yield intermediates that combine features of both. Named clones and hybrids are usually maintained vegetatively to preserve their exact character.
Common problems
- Rot — the commonest cause of loss, almost always from overwatering or a slow-draining mix; the leaves or base become soft and translucent-brown. Keep the mix gritty and let it dry between waterings.
- Scorched or marked windows — too much direct sun can leave permanent scars or a reddish, stressed cast on the exposed leaf tops.
- Shrivelled, receding leaves — usually underwatering or a lost root system; check the roots and resume careful watering.
- Pests — mealybugs (white fluff between the leaves and at the roots) and, less often, root mealybugs and fungus gnats in damp soil. See Pests and diseases.
See also
- Haworthia — the genus overview
- Haworthia maughanii — the closely allied form (often treated as H. truncata var. maughanii) it is frequently crossed with
- Soil and potting mix · Watering · Propagation — leaf · Propagation — offsets · Repotting