Xerophyte

Central Spines

Not present or (usually) 1 to 6 very short, yellow to pinkish to brownish, more or less erect or diverging, 1-25 mm long.

Description

The rainbow cactus (Echinocereus pectinatusSN|8509]]SN|8503]]) commonly remains single, but old plants sometime branch and form a a loosely clumped cluster. It has yellow, pinkish or brownish spines loosely pressed to the surface or spreading widely, pectinate, and intertwining with those of the other areoles. It produces very beautiful, brilliantly coloured flowers with spiny tube, which later develop into Gooseberry-like fruits rich in sugar and said to be very delicious. Two subspecies are recognized by Anderson (2001 ), the nominate, and subsp. wenigeri (L.D.Benson) W.Blum & Rutow. A third supecies, subsp. ctenoides (Engelm.) G.Frank, is included here by Hunt et alt. (2006), but Anderson placed it in Echinocereus dasyacanthusSN|5533]]SN|5533]] Engelmann).

Similar Species

E. pectinatus, with at least microscopically visible stubs of central spines is superficially similar to the unrelated Echinocereus rigidissimusSN|8503]]SN|8509]], belonging to the Echinoceeus reichenbachii group, which always lacks central spines. Botanists sometimes lump this species with the yellow-flowered Texas rainbow hedgehog, Echinecereus dasyacanthus, or consider them varieties of a single species.

Flowers

Funnel-shaped, borne on the sides of the stems, diurnal, intense pink (but also magenta, lavender...or...yellow to near-whitish) with a white-greenish base, (5-)6-88-15) cm long and in diameter. Petals quite long and pointed, areoles very spiny with white hairs on the floral tube. Stamens usually cream coloured.Blooming season. Spring—summer.

Ribs

(12-)20-23 obtuse, usually straight forming low tubercles.

Stem

Usually solitary, globose to cylindrical (8-)10-20(-35) cm tall 3-6(-13) cm in diameter almost hidden by the short interlocking spines.

Radial Spines

(12-)16-30 white or pinkish 5-10 mm long, usually closely pressed to the surface or spreading widely, pectinate, and intertwining with those of the other areoles pinkish to grayish, often in coloured bands.

Fruits

Spiny, globose to elliptical, greenish-purple, fleshy, becoming naked, 2-3 cm in diameter. Gooseberry-like rich in sugar and said to be very delicious.

Areoles

Approximate, but not touching one another, about 3 mm long, oval, young areoles with short white hair.