Xerophyte

Seeds

Pale yellow, angular to squarish in outline, warped, 4-6 × 3.5-5 mm, sides smooth, each with 2-4 large depressions.

Description

The silver cholla or golden cholla (CylindrSN'>27954' alt='16223'>Opuntia ramosissima#SN#27958'>Cylindr[[Opuntia ramosissimaSN' style='border

Remarks

A dwarf form, with narrow terminal stem segments bearing few spines per areole, and one spine longer than the others, occurs on the very arid flats along the lower Colorado River in California and Arizona and has been recognized as Opuntia wigginsiiSN|7631]]SN|16228]]. Although exceptions occur, plants to the north and west in the range tend to be more spiny and to bear yellow to yellow-green flowers. C. echinocarpa has been shown to hybridize with Cylindropuntia whippleiSN|7630]] (Cylindropuntia x deserta), CylindrSN'>7630' alt='16228'>Opuntia acanthocarpa#SN#7631'>Cylindr[[Opuntia acanthocarpaSN' style='border

Note

This species has tubercles 1-2 time long than wide and the terminal joints are less than 12 cm long.Derivation of specific name Echino means "prickly" or "spiny" and carpa means "fruit."

Flowers

Light green to yellowish green and sometimes tinged orange, 2-2.3 cm long and somewhat persistent on the fruit. Inner tepals spatulate, 20-23 mm long, emarginate-apiculate. Filaments are greenish-white to yellow, sometimes suffused with bronze or rose, but not red; anthers yellow. The style and stigma lobes are white, cream to light green.

Glochids

Yellow, very small but conspicuous (3-5 mm long).Spines 6-22 on most areoles, straight, prominent on distal ones, interlaced and obscuring stems, white, greyish, yellowish to brown, sometimes darker, erect to spreading, 2.2-5 cm long, often accompanied by 0-5 bristle-like spines at areole margins obscuring stems, sometimes brushlike. Sheaths range from white below golden yellow aboveand are baggy.

Stem

0.5-2 m high much branched. Stem segments usually firmly attached, terminal segments sometimes easily detached, cylindrical, green to light grey-green, 3-7.5(-12) cm long, sometimes as long as 12 cm, and 1-2.5 cm in diameter, with distinct fleshy tubercles 4-13(-15) mm long, moderately broad. The width of the tubercles is less than twice the length, which helps to distinguish it from buckhorn cholla (Cylindropuntia acanthocarpa), which occurs in a similar geographical distribution.

Fruits

Becoming dry upon maturation, spherical or obconical to very shallow saucer-shaped with apical flange around deep umbilicus, dry, densely spiny, tan, 1.3-2.3 cm long, 1.1-2 cm in diameter with few large seeds. Areoles 16-24(-36). Very few fruits reach maturity, and many immature fruits can often be seen lying on the ground below.

Areoles

White, yellow, or tan becoming grey, round to broadly elliptical 4-4.5 × 2-3.5 mm.