Graptopetalum
Graptopetalum is a small genus of rosette-forming succulents in the stonecrop family Crassulaceae, native to Mexico and the southwestern United States (chiefly Arizona). The name means "marked petal", a nod to the fine spots and bands that speckle the star-shaped flowers. Grown for their soft pastel foliage in shades of grey, lavender, pink and powder-blue, these easy-going plants are famous for rooting from little more than a fallen leaf. They are commonly called leatherpetal, a name that refers to the thick, leathery texture of their small flower petals.
Description
Graptopetalum species form tidy rosettes of thick, fleshy leaves, either stemless and hugging the ground or lifted on trailing, sprawling stems that lengthen with age. The leaves are typically broad and pointed, often coated in a waxy, powdery bloom (a farina) that gives the plant its characteristic pastel, almost ghostly finish and rubs off easily where handled. Colours shift with light and season, drifting between grey-green, bluish, lilac and pink.
The flowers are the family signature: small, star-shaped and five-petalled, borne on slender side stalks in spring. Close inspection shows the pale petals are freckled and streaked with red or maroon — the "marked petals" that name the genus. Individually modest, they open in loose sprays above the rosette.
The genus is closely related to Echeveria, Sedum and Pachyphytum, and crosses freely with all of them, which is why Graptopetalum turns up so often in the parentage of hybrid succulents.
Distribution and habitat
Most species come from the mountains and canyons of northern and central Mexico, with a couple ranging north into Arizona. They are plants of rocky ground — cliff faces, ledges and gravelly slopes — where they root in shallow pockets of gritty soil with excellent drainage and enjoy bright light with a measure of seasonal drought.
Notable species
- Graptopetalum paraguayense — the ghost plant or mother-of-pearl plant, the most widely grown species; forms trailing stems of pearly grey-pink rosettes and is famously tough and forgiving.
- Graptopetalum bellum — once placed in its own genus as Tacitus bellus; a flat, tight rosette prized for unusually large and vivid star-shaped magenta flowers.
- Graptopetalum amethystinum — the jewel-leaf plant or lavender pebbles, with plump, rounded leaves flushed lilac and pink.
- Graptopetalum mendozae — a miniature, densely clustering species with small pastel rosettes, popular for dish gardens.
- Graptopetalum pentandrum — a lax, open rosette in soft blue-grey to lavender tones.
Cultivation
Graptopetalum are among the more beginner-friendly succulents. Grow them in a very free-draining, mostly mineral potting mix and give them the brightest light you can — strong sun deepens the pastel colours and keeps rosettes compact, while too little light makes them stretch, pale and lose their symmetry. Water thoroughly once the soil has dried out completely, then hold off; like most Crassulaceae they resent sitting wet and are far more often lost to overwatering than to drought. Ease back sharply in winter. Most tolerate light frost only briefly, so keep them frost-free or bring them under cover in cold climates. See Watering and Repotting for general technique.
Handle plants by the stem rather than the leaves where possible — the powdery bloom does not grow back and fingerprints show as permanent marks on the foliage.
Propagation
Few plants propagate more willingly. A single fallen leaf, laid on the surface of a gritty mix, will usually root and raise a tiny new rosette at its base. Whole rosettes and stem cuttings root just as readily; simply let the cut end callus for a day or two, then set it on dry, well-drained soil. Species also grow easily from seed, though hobbyists rarely need to bother. See Propagation — leaf, Propagation — cuttings and Propagation — offsets.
Hybrids and cultivars
Because Graptopetalum hybridises so readily with its relatives, it is a cornerstone of the intergeneric "graptos" that fill succulent collections:
- ×Graptoveria — crosses with Echeveria, combining graptopetalum hardiness with echeveria colour and form.
- ×Graptosedum — crosses with Sedum, giving vigorous, colourful trailing rosettes.
- ×Graptophytum — the rarer cross with Pachyphytum.
These hybrids share the same easy care as the parent genus and are worth seeking out for their range of pastel and sunset tones.
Common problems
- Rot — from overwatering or a poorly draining mix; rosettes soften and collapse from the base.
- Etiolation — insufficient light causes stretched, spaced-out rosettes on elongated stems.
- Pests — mealybugs (white fluff nestled between the leaves) and, less often, aphids on flower stalks; see Pests and diseases.
- Marred bloom — the waxy coating rubs off permanently where touched, leaving fingerprints and blemishes.
See also
- Echeveria · Sedum · Pachyphytum — closely related genera it hybridises with
- Soil and potting mix · Watering · Propagation — leaf · Propagation — cuttings