Xerophyte

Habit

Shrubby or tree-like 1.5-2 m 1-2 m tall, with a commonly branched trunk. The crown may be open to compact and usually bears whorled branches.

Seeds

Pale yellow, rounded to angular or squarish in outline, flattened to warped, 3.5-4 mm long, 3-4 mm wide.

Description

Opuntia x kelvinensis is a natural intergeneric hybrid between Opuntia fulgida and Opuntia spinosiorSN|16252]]SN|16252]]. It is trunked but intermediate in growth form, joint, size, and ease of detachtability. Spine length is intermediate too, but the spines are grey to pink. Flowers, variably coloured, are diurnal and many tepaled. The fruit is intermediate in colour, tubercle size, and depth of apical cavity. To complicate matters, there are two clones In Pima country

Stem Segments

Often easily dislodged, if terminal, green or purple, 5-13 long, 1.8-3 cm in diameter.Tubercles prominent, broadly oval, 0.7-1.2(-1.5) cm long.

Flowers

Variably coloured, diurnal and many tepaled. Inner perianth segment rose to magenta, spatulate, 18-25(-30) mm long, with a short, sharply pointed tip. Filaments deep rose. Anthers yellow; style white, tinged red-purple distally; stigma lobes white with hint of green.

Glochids

Inconspicuous, longer in the upper part of the areole, yellow, to 1 mm long.

Blooming Season

Flowering spring (Apr-Jun).

Spines

0-8(-13) per areole, sometimes with 1-3 bristle-like spines along areole margins at most areoles, usually slightly interlacing with spines of adjacent areoles, pale-yellowish to tan, sometimes with pinkish hue, to red-brown and partially grey coated, aging brown-grey to grey. lowermost spines often angular-flattened, reflexed, the longest to 30 mm long. Uppermost spines straight, erect-divergent, the longest to 18 mm long. Sheaths uniformly whitish or tipped yellow to gold, slightly baggy.

Fruits

Usually sterile, sometimes forming short chains, yellow-green to yellow, sometimes purplish, 25-45 long, and 15-22 mm in diameter, fleshy, tuberculate, spineless; tubercles progressively longer toward fruit apex; umbilicus 4-7 mm deep; areoles 32-44.

Areoles

Triangular to rhombic, 4.5-6 long, 3-5 mm broad, with yellow wool, ageing grey to black.