Xerophyte

Seeds

Ovoidal, brown to black.

Description

Acanthocalycium spiniflorumSN|74]]SN|74]] (Echinopsis spinifloraSN|72]]SN|72]]) is usually solitary or slowly branching through basal shoots, it can become an upright cactus with stems that can reach a height of about 15 cm. The spines are arranged neatly in rows down the stem. The showy flowers range from white to pinkish lilac and are about 4 cm across. It is a pretty variable species.

Note

Acanthocalycium spiniflorum - both the genus and species names refer to the characteristic spiny flower tube.

Flowers

Bell-shaped to funnelform, erect, 4-5 cm long, 4 cm in diameter, on lateral areoles close to the stem apex, and the segments of the perianth are pale mauve, pink or white. Pericarpel and floral tube green, with dense, narrow, spine-tipped brownish scales approximatively 1 cm long , sparsely hairy in their axils. Stamens in several rows, incurred, with no separate throat-circle. Stigmas 6 mm long, pale green. Flower-buds very hairy.

Chromosome Number

2n = 22

Spines

10-20, straight, needle-like, flexible, yellowish to brown, with dark tips, becoming grey with age all more or less of the same length in a given plant (0,5-4 cm), but this species appears to be very variable about the length colour and number of spines in different population. They usually are black or light brown at first, becoming grey or whitish-yellow as they ages.

Ribs

About 16-20, acute, somewhat tuberculate, to10 mm high.

Stem

Usually single spherical, depressed apically, in time becomes slightly cylindrical, growing in habitat to a height of 12-15 cm, and a diameter of 6 to 10 cm, but can reach a height of almost 60 cm and be over 15 cm in diameter in a heated greenhouse or outdoors where winters are warm. The epidermis is pale to dark green.

Fruits

Globose, about 1 cm in diameter, firm, with persistent scales, splitting vertically when ripe.

Areoles

At the apex of tubercles, 1.5-2 cm apart, at first covered with yellowish-brown felt. The lower part of the areola is elongated while the upper part curves around the sides of the rib, more or less in the shape of a small shield. As the tubercles widen in the course of growth, the areoles become elliptical and almost glabrous.