Xerophyte

Central Spines

1-6, very slender, straight, brownish, dark brown to black with whitish bases, 3-25 mm long (mostly about 17 mm), lowermost one longest and perpendicular to stern, others ascending and diverging.

Seeds

Oval, 1-1,2 mm in diameter, dark brown to black, warty.

Description

Echinocereas chisoensis(sometimes spelled "chisosensis") is a rare cactus species known by the common name "Chisos Mountain hedgehog cactus" with fantastic flowers. The base of the petals is deep crimson followed by a pinkish-white band and a pink-purple or rose-coloured tip. The bright green stygma lobes stand out over a bed of creamy anthers.

Roots

sometimes thickened.

Tubercles

6-8 mm apart.

Flowers

Funnelform, from near the top of plant and below, light pinkish to magenta with white (or at least paler) throats and dark crimson centers, about 6-6,5 cm long, 2,5-7 cm in diameter (but up to 9,5 long and 12 cm in diameter in var. fobeanus) often not opening widely if shaded. Floral tube greenish, woolly, with evenly spaced clusters of hairy or bristly, brown-tipped spines (resembling those of the closely related Echinocereus reichenbachiiSN|21781]]SN|7575]]). Inner perianth parts in two whorls, pointed, remaining upright, characteristically deep red near the base. Stamens with white or pink filaments and pale yellow anthers. Style whitish, exerted with about 10 green stigma lobes.Phenology It blooms in spring in spring ( In habitat usually in March-April, perhaps to July; fruit mature in about one month in May-June, perhaps as late as August). Flowers open mid-morning and close at night and again for 1 to 3 days.

Chromosome Number

2n = 22.

Ribs

10-16, vertical or more or less spiralled, strongly tuberculate.

Stem

Cylindrical, erect or ascending, tapering toward the tips, not annually constricted, 5-25(-30) cm high, 3-5 cm in diameter. Healthy stems are light green, grey-green to blue-green, but take a reddish-maroon tinge when stressed.

Fruits

Oblong, narrowly obovoid or club shaped, to 18-37 mm long, 10-15 mm in diameter, green to reddish, more or less covered with woolly areoles bearing bristly or hair-like spines, but ultimately the areoles are deciduous. The fruit is fleshy and splits open on one side at maturity. Pulp is whitish, mucilaginous or nearly dry.

Habit

Perennial stem succulent, solitary or few branched.

Note

Echinocereas chisoensis is easily tell apart from other Texan echinocerei by the usually solitary, large, ribbed, tuberculate stems, with spines not obscuring the surface; and the floral tube with its covering of wool and bristly, hair-like spines. When not in flowers it may be confused with Echinocereus viridiflorus var. russanthusSN|7575]]SN|21781]] and perhaps Echinocereus dasyacanthusSN|5533]]SN|5533]].

Radial Spines

11-17, slender, whitish or ashy to pinkish-gray, often with brown to maroon tips tending to diverge, not pectinate, uppermost ones tiny and bristle-like 16-32 mm long, lowermost 6-20 mm long.

Areoles

Distinctly woolly, especially in enlarged flower-bearing areoles, almost circular when young, about 2 mm long but becoming elliptic and bare with age.