Xerophyte

Leaves

Subulate, curved backward, pale green 3-6(-8) mm long.

Description

Opuntia dilleniiSN|9698]]SN|16273]] is a low, spreading bush growing in broad clumps and often forming dense thickets, or tall and much branched, 2 to 3 meters high, sometimes with distinct terete trunks.

Roots

Shallow enabling to exploit limited rainfall, and rich in root hairs. Associations with fungi and bacteria can improve the capture of mineral nutrients.

Stem Segments

Joints obovate to oblong, 7 to 40 cm long, 6-15(-20) cm wide, 1 to 2 cm thick, succulent, spiny, the margin more or less undulate, dull green or bluish green, somewhat glaucous, but bright green when young and irregularly trimmed with relatively few areoles.

Note

There is considerable dispute whether Opuntia dilleniiSN|16273]]SN|16273]] belongs in Opuntia strictaSN|16273]]SN|9698]] or should be distinct.

This member of the Cactaceae family was given this name by Johann Jacob Dillenius (1648–1747), a German botanist and Professor of Botany at Oxford.

Flowers

Variable. In the typical form lemon-yellow to yellowish orange to orange, in some forms red from the first, 7 to 8 cm long. The perianth is rotate and reddish. Petals broadly obovate, 4 to 5 cm. long. The stamens are numerous and longer than the corolla, filaments greenish yellow. The style is stout, thick, white and there are 5-8 erect white stigmas-lobes.

Chromosome Number

2n = 22.

Spines

Extremely variable, spreading in a ll directions, usually 1-6, sometimes none, sometime 10 from an areole on first year joints, usually more or less flattened and curved, sometimes terete and straight, yellow, more or less brown-banded, or mottled, often brownish in age, 2.5-3.8 cm long, sometimes 5(-7) cm long, sometimes few or none.

Fruits

Pear-shaped to subglobose, truncate, depressed at the apex, narrowed at base, 5 to 7.5 cm long, deep reddish-purple when ripe, spineless, and bearing tiny tufts of glochidis. The fruits are edible. The juicy flesh of fruits is purple and contains many rounded seeds which are with an arillus-like envelop, about 4 mm in diameter and tan coloured.

Areoles

Areoles somewhat elevated. Often large, filled with short brown or white wool when young, usually few and remote, on old joints 10 to 12 mm in diameter, glochids (short barbed bristles) numerous, conspicuous yellow up to 13 mm long forming striking tufts; wool in areoles short, sometimes brown, sometimes white.