Pachyphytum
Pachyphytum is a small genus of leaf succulents in the stonecrop family Crassulaceae, endemic to Mexico and closely related to — and freely hybridised with — Echeveria. The name comes from the Greek for "thick plant," a fitting description of the genus's characteristically fat, turgid leaves, most of which are cloaked in a chalky white farina (epicuticular wax) that gives them a frosted, pastel look. Growers prize them as the plump-leaved cousins of the more familiar rosette echeverias.
Description
Pachyphytum species are small evergreen perennials that form loose rosettes or short, sprawling stems clothed in exceptionally plump, water-storing leaves. The leaves are the genus's defining feature: rounded, egg-shaped or club-like, often almost cylindrical, and thick enough to feel firm and heavy for their size. Most are coated in a fine powdery farina that scatters light into soft blues, lavenders, pinks and pale greens; this bloom rubs off easily where the leaves are handled, leaving a permanent fingerprint, so plants are best moved by the pot or stem.
As stems lengthen they tend to lean and trail, and older plants often develop a short, gnarled caudex-like base. The flowers are borne on an arching, one-sided flower spike and are typically bell-shaped and nodding, in shades of red, orange, greenish-white or pink, frequently with colourful bracts along the stalk. Like many Crassulaceae, the genus uses CAM photosynthesis, opening its pores at night to conserve water in a dry climate.
Distribution
The genus is endemic to Mexico, where the species grow on rocky slopes, cliffs and ledges — often in the central and eastern highlands — rooted in thin, gritty mineral soils among rocks. These habitats are bright, sharply drained and subject to seasonal drought, which is exactly the regime the plants expect in cultivation.
Notable species
- Pachyphytum oviferum — the "moonstones," with rounded, farina-frosted leaves in pastel pink and lilac; the best-known species in the hobby.
- Pachyphytum compactum — "little jewel," with smaller, angular, faceted leaves marked by pale lines.
- Pachyphytum bracteosum — larger, spoon-shaped, heavily farinose leaves and showy bracted flower spikes.
- Pachyphytum hookeri — slender, pointed, cylindrical leaves on lengthening stems.
- Pachyphytum glutinicaule — sticky-stemmed species with elongated, tinted leaves.
Cultivation
Pachyphytum are undemanding if their two main needs — strong light and a dry root run — are met. Give them the brightest position available, ideally a few hours of direct sun; too little light stretches the stems and dulls the leaf colours and farina. Grow them in a very free-draining, mostly mineral mix and water only when the soil has dried right through, watering more generously in the warm growing season and keeping them nearly dry through a cool winter rest. As with most Mexican Crassulaceae, overwatering — especially in cold or dark conditions — is the commonest cause of loss.
Protect the plants from hard frost; they are happiest in the mild, frost-free conditions of USDA zones 9b–11, or as bright windowsill and greenhouse plants elsewhere. Handle them as little as possible to preserve the delicate farina, and see Watering and Repotting for general technique.
Propagation
Pachyphytum propagate very easily. Individual plump leaves, gently detached so the whole base comes away cleanly, will callus and then root and pup at the base to form new plantlets; stem cuttings of leggy plants root readily as well. Allow all cut or detached surfaces to dry for a few days before setting them on a barely-moist mineral mix. Seed is possible but slower and mainly of interest to hybridisers. See Propagation — leaf cuttings, Propagation — cuttings and Propagation — seed for details.
Hybrids and cultivars
Pachyphytum crosses readily with Echeveria, producing the popular intergeneric hybrid genus ×Pachyveria, which combines the plump leaves of Pachyphytum with the rosette form and hardiness of Echeveria. Within the genus itself, selected forms and named clones of species such as Pachyphytum oviferum and Pachyphytum compactum are grown for particularly intense leaf colour or compact habit. Because the pastel farina is so much a part of their appeal, cultivars are generally selected for good bloom and colour rather than for the extreme variegation or cresting seen in some other succulents.
See also
- Echeveria — the closely related sister genus
- ×Pachyveria — Pachyphytum × Echeveria hybrids
- Crassulaceae — the stonecrop family
- Soil and potting mix · Watering · Propagation — leaf cuttings · Repotting