Xerophyte

Trunk

At first very spiny and made up of flat joints set end to end, with the short axis of each joint at right angles to that of the adjacent joint, in time becoming terete, and when old some-what woody, nearly naked, 30 to 130 cm in diameter; bark of old trunks smooth, covered with reddish-brown or reddish black platelets and peeling off in thin layers. The trunk becomes thicker than that of any other known species of the genus.

Leaves

Conical, large, 2-9 mm long, nonpersistent, usually not obvious.

Cladodes (joints)

Orbicular, oblong or obovate, fleshy, usually very large, 15 to 38 cm long, 15-27 cm wide, 1-3,5 cm thick, very spiny, green to yellow-green, 22-38 cm long.

Seeds

Large, 5 to 6 mm broad, white to light brown, covered with soft hairs, 2-5 mm long.

Description

Opuntia galapageiaSN|18105]]SN|18105]] is a a very variable perennial prickly pear species, sometimes low and creeping, but often becoming very large, arborescent and arboreal, 2,5-5(or more) meters high, with a well-developed, large top either open or very compact and rounded. It show a great range of variation in habit, armament of joints, and character of spines. The greatest range of spine characters is shown between the young plants and old ones and between the trunk and the joints. These differences are very marked, but seems to be of little value. Opuntia galapageiaSN|18105]]SN|18105]] has received numerous names (at least 16), representing no more than local phenotypes, of which only three varieties are usually recognized

Flowers

Solitary, diurnal, yellow or orange, 4-7,5 cm long, 3,5-6 cm broad. Ovary more or less tuberculate. Inner perianth parts yellow, 1,7-4 cm long. Stamens numerous.

Glochids

Few or absent.

Spines

5-35, extremely variable (dimorphic), but nearly all straw-yellow (but also orangish, brown, or white), becoming reddish or brownish white; few on young joints of vigorous plants, very stout, pungent, long and rigid, very unequal, the longest 7 to 8 cm long; joints of old plants bearing several, erect, more or less pungent bristles or sometimes very weak soft hairs instead of spines, 2,5-7,5 cm long, while the spines from the trunks often are very stout and sometimes 40 in a cluster.

Fruits

A berry, globose to oblong, 2-6 cm long, 2-4 cm in diameter, fleshy with numerous seeds, green to yellowish green or brownish, sometimes borne in the ends of joints, more or less spiny with a few glochids.

Areoles

Large, 2-7 mm broad, typically 2,5-3,4 cm apart, often prominent on the trunk, there especially forming knobs bearing numerous spines. Trichomes few to many, to 4 mm long