Echinocactus Link & Otto

Barrel Cactus

Greek echinos—hedgehog.

Body mostly solitary with huge barrel-like to cylindrical strongly ribbed stems. Areoles large, elongated and more or less continuous in mature plants and forming a woolly crown on the body; nectar secreting glands absent. Spines strong. Flowers arising at the body apex, funnel to bell-shaped mostly pink or yellow; summer. Pericarpel with narrow scales bearing wool in their axils. Fruit pale yellow, fleshy to almost dry.

The 3 commonly grown species are keyed out in the key. E. horizonthalonius Lem. may, like E. texensis Hopffer, be better placed in Homalocephala Britton & Rose, while E. platyacanthus Link & Otto is often grown under the synonym E. ingens Zucc.

Ferocactus is rather similar but has the nectar-secreting glands on the areoles.

This genus at one time contained nearly all the cacti with ribbed stems, other than those in Cereus and Melocactus; it is now best known through the huge E. grusonii which forms large spiky balls characteristic of globose cacti.

Large barrel-shaped to cylindrical, srongly ribbed, thickly spined bodies

3 species as considered here from N Mexico and SW USA.

Source: Thompson, A, ; Forbes, S.; Spencer, R. (1997). Cactaceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 2. Flowering plants. Dicotyledons. Part 1. The identification of garden and cultivated plants. University of New South Wales Press.

kingdom Plantae
phylum   Tracheophyta
class    Magnoliopsida
superorder     Caryophyllanae
order      Caryophyllales
family       Cactaceae
Higher taxa
Subordinate taxa
species         Echinocactus gielsdorfianus Werderm.