Hamatocactus
Hamatocactus is a small genus of ribbed barrel cacti from the southwestern United States and northern Mexico, best known for their prominent hooked central spines and cheerful funnel-shaped flowers. The name comes from the Latin hamatus ("hooked"), a nod to the fish-hook central spine that gives most species their character. It has long been a contested genus: many botanists fold its members into Thelocactus or Ferocactus, and you will often find the same plants sold under all three names.
Description
Hamatocactus species are small to medium solitary cacti with cylindrical or somewhat globular, strongly ribbed bodies. The ribs are usually deep and can be more or less wavy or tubercled, carrying well-spaced areoles. Each areole bears a spreading crown of slender radial spines and one or more longer central spines, at least one of which is characteristically hooked at the tip — the feature that unites the genus and gives it its name.
Flowers appear from areoles near the crown, mostly in the warmer months. They are funnel-shaped and often quite large for the size of the plant, typically in shades of yellow, frequently with a contrasting red or orange throat. Blooms are followed by small fleshy fruits that ripen and split to release the seed.
Distribution
The genus is native to arid and semi-arid country in the southwestern United States — chiefly Texas and New Mexico — extending south into the neighbouring states of northern Mexico. Plants grow in gravelly, rocky or sandy ground in desert scrub and grassland, often among rocks and low shrubs that provide a little shelter from the most intense sun.
Notable species
- Hamatocactus setispinus — the twisted-rib cactus, the most widely grown member and the classic hobby plant of the genus; free-flowering with yellow, red-throated blooms. Often listed as Thelocactus setispinus.
- Hamatocactus hamatacanthus — the Texas turk's-head or fish-hook barrel, a larger species with long, strongly hooked spines; frequently treated as Ferocactus hamatacanthus.
- Hamatocactus uncinatus — sometimes placed here, with dark hooked centrals and reddish-brown flowers; also classified under Glandulicactus or Sclerocactus.
Cultivation
As a group these are among the more forgiving barrel-type cacti and make good subjects for the keen beginner. Grow them in a very free-draining, mostly mineral mix in a pot that is not too large, and give them the brightest position you can — full sun suits them and keeps the spination strong and the body compact. Thin, pale, upward-domed growth is a sign of too little light.
Water generously during the warm growing season once the soil has dried, then taper off as autumn arrives and keep the plants dry and cool through winter. This dry winter rest not only prevents rot — the usual cause of loss — but also encourages a good show of flowers the following season. See Watering and Repotting for general technique, and Pests and diseases for dealing with the mealybugs and red spider mites that occasionally trouble them.
Propagation
Seed is the standard and most reliable method; the seeds germinate readily on a warm, gritty surface kept humid, and this is how most collection plants are raised. See Propagation — seed for a full walkthrough. The species are generally solitary and seldom offset, so vegetative propagation from offsets is uncommon; where a grower wants to speed up a slow seedling, grafting onto a vigorous rootstock is an option.
Hobby and taxonomy notes
For the collector, the chief thing to know about Hamatocactus is its unsettled classification. Because the genus has repeatedly been merged into Thelocactus and Ferocactus (and its species scattered among still other genera), the same plant may reach you under several different labels. None of this affects how you grow it — care is the same whatever the current name — but it is worth keeping the synonyms in mind when buying seed or plants so you don't end up with unintended duplicates. The hooked spines and generous yellow flowers make the group a rewarding and characterful addition to a mixed cactus collection.
See also
- Thelocactus · Ferocactus — the genera into which Hamatocactus is often merged
- Grafting · Soil and potting mix · Watering · Propagation — seed · Pests and diseases