Lophophora diffusa
| Light | Bright light with some shade from the harshest afternoon sun |
|---|---|
| Water | Sparingly; allow to dry fully between waterings, keep dry in winter |
| Soil | Gritty, mostly mineral, fast-draining mix (see Soil and potting mix) |
| Temperature | Keep above freezing; roughly USDA zones 9b–11 |
| Propagation | Seed (primary); grafting to speed growth; occasional offsets |
| Toxicity | Contains bitter, psychoactive alkaloids (chiefly pellotine); best kept away from pets and children — see Legal status below |
Lophophora diffusa is a soft, slow-growing, spineless cactus with a low, rounded body and a smooth, yellowish- to greyish-green skin. Unlike its famous relative L. williamsii, its ribs and tubercles are poorly defined — often little more than gentle, flattened humps — giving the plant a distinctly rounded, almost blob-like outline. It is endemic to a small area of the state of Querétaro in central Mexico, and is one of the two or three species usually recognised in the genus Lophophora.
Description
Lophophora diffusa forms a solitary or clustering, flattened-globular body, typically a few centimetres across and rising only slightly above soil level. The skin is firm, spineless and rather soft to the touch, and its colour tends toward a pale yellow-green — noticeably lighter than the blue-green of L. williamsii. The ribs are broad, low and irregular, so the body often looks smooth and only weakly divided rather than crisply ribbed.
Tufts of whitish or yellowish wool sit in the areoles running along the top of the plant. Small flowers open from this woolly crown, usually whitish to yellowish-white, appearing over the warmer months. As with other Lophophora, mature plants develop a stout, carrot-like taproot that stores water and anchors the plant deep in the ground.
Distribution and habitat
The species is a narrow endemic, restricted to a small region of Querétaro in central Mexico. There it grows in dry scrub and grassland on limestone-derived soils, often nestled among low shrubs and grasses that shade the flat top of the plant and shelter it from the fiercest sun. In habitat, plants can shrink back into the soil during drought, leaving little more than the crown visible.
Because its natural range is so limited, wild populations are vulnerable to habitat disturbance and illegal collection. Like the entire cactus family, Lophophora is listed under CITES Appendix II, so international trade in wild plants is regulated. Nursery-propagated seedlings, however, are widely grown by hobbyists.
Cultivation
Lophophora diffusa is grown much like other slow, taprooted desert cacti. Give it a deep, gritty, mostly mineral mix in a pot deep enough to accommodate the taproot, and site it in bright light with a little shade from intense afternoon sun. Water thoroughly only once the soil has dried out completely, then let it dry again; keep the plant dry and cool through winter, which both prevents rot and encourages flowering.
The species is naturally slow, and overwatering — especially in a heavy, water-retentive soil — is by far the most common cause of loss. Many growers speed up young plants by grafting seedlings onto a vigorous rootstock, growing them on before returning them to their own roots. See Repotting for handling the brittle taproot.
Propagation
Seed is the standard and most reliable method. Sown on a warm, mineral surface and kept humid, the seeds germinate readily, though seedlings grow slowly and benefit from patience. Plants that cluster can sometimes be divided, and offsets — where produced — may be removed and rooted, but vegetative increase is uncommon outside of grafting. See Propagation — seed and Propagation — offsets for technique.
Common problems
- Rot — almost always from overwatering or a slow-draining mix; the soft body discolours and collapses, often from the base or crown.
- Etiolation — too little light makes the body pale, soft and elongated, losing its natural low, rounded form.
- Pests — mealybugs (white fluff in the crown and on the roots) and red spider mites are the usual offenders. See Pests and diseases.
Legal status
Chemically, Lophophora diffusa differs markedly from peyote (Lophophora williamsii): it contains mainly pellotine and little or no mescaline. Despite this, the plant is frequently swept up in restrictions aimed at peyote, because the two are closely related and difficult to tell apart at a glance. The genus is also listed under CITES Appendix II, which regulates international trade in the plants.
Legal treatment of Lophophora varies considerably between countries and jurisdictions, and rules that name peyote or mescaline may or may not extend to L. diffusa. Growers should check the laws that apply where they live before acquiring or trading plants. This article is horticultural reference only and does not describe any use of the plant beyond growing it as an ornamental cactus.
See also
- Lophophora — the genus overview
- Lophophora williamsii — the closely related peyote
- CITES · Grafting · Soil and potting mix · Watering · Propagation — seed