Hamatocactus uncinatus
| Light | Bright light; some protection from the fiercest summer sun |
|---|---|
| Water | Moderate in growth; allow to dry between waterings, dry winter rest |
| Soil | Gritty, fast-draining mineral mix (see Soil and potting mix) |
| Temperature | Cold-hardy to roughly −11 °C (12 °F) if kept bone-dry; about USDA zone 8 and warmer |
| Propagation | Seed |
| Toxicity | Non-toxic to cats and dogs |
Hamatocactus uncinatus is a solitary, cylindrical to barrel-shaped cactus from the Chihuahuan Desert of northern Mexico and the southwestern United States, easily recognised by its long, fiercely hooked central spines and its unusual dull brownish-red flowers. The strongly hooked "fishhook" spines give it the common names cat claw cactus and brown-flowered hedgehog. It is a taxonomically much-shuffled species — long treated in Hamatocactus, it is now often placed in the genus Glandulicactus, and has also been shunted through Sclerocactus and Ferocactus over the years.
Description
Hamatocactus uncinatus forms a firm, ribbed body that is usually cylindrical to short-barrel-shaped, growing to roughly 10–20 cm tall and staying solitary in most plants. The ribs are prominent and somewhat tuberculate, carrying widely spaced areoles that bear the plant's most distinctive feature: long, stiff central spines, the lowest of which is dramatically hooked at the tip like a fishhook or a cat's claw. Surrounding radial spines are shorter and straighter. Spine colour ranges from pale straw through amber to reddish-brown, often darkening with age.
A curious detail of the areoles is the presence of small nectar-secreting glands, a feature that helped inspire the segregate genus name Glandulicactus. The flowers are similarly unusual for a barrel-type cactus: rather than the bright yellow or pink of many relatives, they are a muted brownish-red to maroon, sometimes with a greenish or coppery cast, and relatively small, opening near the crown. These are followed by reddish fruits.
Distribution and habitat
The species is native to the Chihuahuan Desert region, ranging across the northern Mexican states (including Chihuahua, Coahuila, Nuevo León and adjacent areas) and reaching into western Texas and southern New Mexico in the United States. It grows on rocky limestone slopes, gravelly flats and open desert scrub, typically among low shrubs and grasses that give a little seasonal shade.
Like all cacti, it is listed under CITES Appendix II, so international trade is regulated; nursery-grown plants are widely and legally available, while collecting from the wild is neither necessary nor permitted.
Cultivation
Hamatocactus uncinatus is a rewarding plant for growers who can resist overwatering, though it has a reputation for being slow and tricky on its own roots. Give it a very gritty, mostly mineral mix and bright light — full sun in cooler climates, with a little shade from the harshest afternoon sun where summers are extreme. During the growing season, water thoroughly but let the soil dry out completely between drinks: the species is notably sensitive to overwatering and prone to rot on its own roots. Keep it dry and cool through winter to prevent rot and to encourage the following season's flowers; kept bone-dry, it is surprisingly cold-tolerant and will take hard frost well below freezing. See Watering and Repotting for general technique.
A practical warning: the long hooked central spines readily snag on skin, clothing and neighbouring plants, so handle the plant carefully and give it a little elbow room on the bench.
Propagation
Seed is the standard and most reliable method, since the species is typically solitary and does not offset freely. Sow on a warm, mineral surface kept humid until germination, then grow the seedlings on hard and bright. See Propagation — seed for a full walkthrough; for the rare clustering plant, offsets can be treated as described in Propagation — offsets.
Common problems
- Rot — the usual cause of loss, almost always from overwatering or a slow-draining mix; the body softens and discolours from the base.
- Etiolation — too little light produces weak, elongated growth and poorly developed spines.
- Pests — mealybugs (white fluff in the areoles and among the spines) and red spider mites are the most common offenders. See Pests and diseases.
See also
- Hamatocactus — the genus overview
- Soil and potting mix · Watering · Repotting · Propagation — seed · Pests and diseases