Submitted by: Jim Tanner

Thelocactus are spectacularly beautiful cacti with dense multicolor spination, well shaped tubercles, and large colorful flowers. They have been a favorite with collectors since they were first discovered.

Thelocactus is a small genus in the cactus family, with only 11 or 12 species. In addition to the species, there are also half a dozen legitimate varieties, and a large number of less legitimate varieties that can be found in reference books and collections. The larger number of questionable varieties is due to variability of some of the species between populations from isolated locations.

Thelocactus are found from Southern Texas through central Mexico, mostly in the Chihuahuan Desert, but extending into brushland and thorn scrub in the western parts of its range, and into the Rio Grande Plains region in Texas. Thelocactus bicolor has the largest range, extending from central Chihuahua in the west into Texas in the north, and as far south as San Luis Potosi.

Thelocactus are easily grown, tolerant of heat and moisture, but not cold and moisture. They benefit from protection from being cold and wet, although plants left unprotected during the last several winters survived in good shape. Some species develop fairly large tap roots, and should be planted in deep enough pots to give them room to grow. They are easily propagated from seed, and this is the best way to develop a good collection from different populations. They can also be propagated from offsets, with a cutting allowed to dry, and then replanted. They are sensitive to mealy bug infestations and spider mites, in the same way that all cacti are, but in general are fairly rugged plants.

Although all the species and all the varieties of this wonderful genus are worth growing, a few stand out.
Thelocactus hexaedrophorus has the best tubercles of an any of the Thelocactus, and is a must for any collection.
Thelocactus rinconensis has the largest body of all the species, getting to 8 inches in diameter in cultivation and habitat.

Tom Glavich

LATIN LOOKUP – Loquerisne Latine (Do you speak Latin)?

The meanings of latin plant names on this page – from http://davesgarden.com/guides/botanary/

• bicolor [BY-kul-ur]
  Of two colors.
• heterochromus [het-er-oh-KROH-mus]
  Differing colors.
• leucacanthus [lew-kah-KAN-thus]
  With white spines or thorns.
• setispinus [set-AY-spin-us]
  Bristle-like.
• Thelocactus [thel-oh-KAK-tus]
  From the Greek theles (nipple) and cactus.
• tulensis [too-LEN-sis]
  Of or from El Tule, Mexico.