Xerophyte

Trunk

Generally erect, solitary, usually less than 2 metres tall, main branches few, closely spaced, short, spreading, nearly horizontal, with older branches at base of crown, clinging becoming dark brown or black. Stem segments, terminal, cylindrical, succulent, easily detached from the plant, whorled or subwhorled, green to gray-green, 4-13(-18) cm long (generally less than 10 cm long), and (2-)4-5.5(-6) cm in diameter. Distal segments usually very easily detached (propagules). Tubercle , broadly oval, 4-8(-11) mm long, 3 mm high.Roots.* Fibrous.

Seeds

2.5-4 mm long, 2.2-3.5 mm across, pale yellow, in gelatinous mass, angular to squarish in outline, generally sterile.

Description

The teddy-bear cholla (Cylindropuntia bigeloviiSN|10928]]SN|10928]]) is a perennial, shrub or small erect tree, 0.30 to 1.50(-3) m tall with a distinct trunk. The branches are at the top of the trunk and are closely spaced and nearly horizontal. Lower branches typically fall off, die and fall off, giving the cactus a vertical appearance and the trunk darkens with age. The yellowish spines almost completely obscure the stem with a fuzzy-looking, but impenetrable, defence. The spines are 2.5 cm long and are covered with a detachable, paper-like sheath. Cylindropuntia bigeloviiSN|10928]]SN|10928]] has a soft appearance due to its solid mass of very formidable spines that completely cover the stems, hence the common name Teddy Bear.

Flowers

Yellow-green at the tips of the stems. Usually 3.6 cm in length. Inner perianth (15-)20-25(-40) mm long, yellow-green to whitish, sometimes tipped red, spatulate, yellow. Filaments green, anthers orange. Style light green; stigma lobes light to dark green.

Blooming Season

Spring (March to June) or occasionally in autumn (September)

Chromosome Number

2n = 33 (rarely 22)

Spines

(4-)8-10(-15), per areole, at most areoles, interlaced with spines of adjacent areoles, usually uniformly, diffusely spreading, very sharp and well barbed (10-)15-25(-28) mm long. Younger spines are yellowish or very pale yellow-brown, sheath uniformly whitish translucent or pale yellow to pale brown and turn black with age, which is easily observed by examining the base of a taller plant.

Fruits

The fruit is cylindrical to broadly obconical (15-)22-40 mm long, (8-)16-20(-28) mm in diameter, fleshy-leathery, yellow at maturity, not proliferating, tuberculate, and may or may not have spines or bristles. The fruits usually have no viable seed, as the plant usually reproduces from dropped stems. Umbilicus 8-10 mm deep. Areoles 36-64, evenly spaced.

Areoles

Elliptic-deltate, 5-6 mm long, 3-4 mm wide; wool white-yellow to brownish, ageing grey. Areoles also bear small, barbed, deciduous bristles sometimes called glochids, sometimes extending along areole margins, yellow, 3-4 mm long.