Xerophyte

Habit

It is a small solitary or mound-forming cactus spreading out to 15 cm. It grows quite close to the ground and offsets only with age. It would appear that in cultivation they grow larger and cluster more vigorously than in habitat.

Central Spines

2 to 5 somewhat longer, to 20 mm long creamy white.

Description

Rebutia archibuiningianaSN|4932]]SN|5051]] is probably one of the many geographical forms of the extremely variable Rebutia fiebrigiiSN|5051]]SN|4932]] with glassy-white to yellowish, silky, short spines and light green tubercles thickly covering the body. The body is made invisible by the spines. It produces vibrant orange-red flowers. The dense spines would protect it from the extremes of cold and sunshine.

Tubercles

About 5 mm high conical.

Flowers

Flowers produced basally or halfway up the stems, curving upward, bright orange or vermilion red, funnel-shaped, 25-45 mm long, 4 cm diameter. Tube narrow 10-18 mm long, outside reddish, inside pale. Ovary spherical, about 4 mm wide, with small triangular scales with few white wool and few white bristly hairs. Tepals vermilion red, rather rounded, often slightly serrated, 14-16 mm long, 4-6 mm wide. Filaments white, anthers golden yellow. Pistil white, with 5-6 white stigma lobes 2-3 mm long, slightly protruding the anthers.

Blooming Season

Flowers all tend to come in one late Spring rush, rather than spread over the Summer, and remain open for up to six days.

Spines

30-40, all more or less similar, bristly, glassy-white, creamy-yellow or pale brownish, bristle-like, fine and soft.

Ribs

About 18, straight to spirally arranged tuberculate

Stem

Roundish to slightly elongated, depressed at the top, 50-60 mm wide and tall, dark green, flat, covered by distinctive tubercles similar to a Mammillaria, that are not easy to see through the dense small spines.

Radial Spines

Less than 10 mm long, white.

Fruits

Tiny, spherical, berrylike, about 5 mm wide, greenish or reddish, with few white wool and bristly, hidden among the spines, bursting when ripe.

Areoles

Elliptical, white-tomentose.