Aylostera muscula description


The original description of Rebutia (Aylostera) muscula was published in Taxon (1963) p. 29, the journal of the International Association for Plant Taxonomy, IAPT by Friedrich Ritter. The Latin description is brief and doesn’t completely tie in with Ritter’s accompanying notes in German, which were translated and published in English by J. D. Donald in The Cactus & Succulent Journal of Great Britain 27(1): p. in February 1965 together with a black-and-white photograph.

Here is the text of the description in Latin as published, together with my own translation in English, and an excerpt of Ritter’s notes translated. You should look up the original description for more details.

Rebutia muscula (subg. Aylostera) Ritter & Thiele, sp. nova, a R. albipilosa Ritter (cf. speciem praecedentem 3) recedit: corpore oblongo, viridi, 3-4 cm diam.; costis in tubercula valde distincta solutis; areolis valde remotis; spinis +/- 50, tenuioribus, 2-4 mm longis, rectis, omnibus similibus; tubo florali setis albis obsito; tepalis 20 mm longis, aurantiacis; staminibus biseratis.

Habitat: Narvaez, Dept. Tarcia, Bolivia. Collected as FR753.

English translation

Rebutia muscula (subg. Aylostera) Ritter & Thiele, new species, differing from R. albipilosa (see the 3 preceeding species) [in Taxon 1963] as follows: body elongated, green, 3 – 4 cm in diameter; ribs split into distinct tubercles; areoles very remote [?]; +/- 50 spines, fine, long, erect, all similar; flower tube with white bristles; petals 20mm long, orange, with two series of stamens.

Ritter’s notes

Body: Green, hemispherical, later elongating, somewhat caespitose; individual heads 3-4 cm thick; with only fibrous roots.
Ribs: Resolved into slight four-cornered tubercles ca. 2 mm high; ribs not clearly countable, estimated at between 25-40 in number.
Areoles: Short oval, white felted, raised above the tubercle, 1-1 1/2 mm long, about 2 mm apart from each other.
Spines: Very fine, straight, white, glistening, about 50, 2-4 mm long, those in the middle shortest, spread in all directions and all are about equally thin, soft, not prickly and covering the body like a white pelt. In culture only about 30 spines are observed. Radial and central spines indistinguishable from each other.
Flower: 31/2 cm long, opening 3 cm wide lateral.
Pericarp: Green, with small scales with white woolly hairs and ca. 10 whitish bristles In the axils. Above the pericarp the receptacle is 31/2 mm thick and style and receptacle coalesce for 7 mm.
Nectary: 2 mm long and open.
Calyx: Funnel form above nectary, about 6 mm long, opening about 1/2 cm wide, outside pale olive green, glistening, with green scales, minute woolly hairs and a few soft white bristles.
Filaments: Whitish, 7-8 mm long, in two series, inserted in pairs between the lower part of the calyx and the calyx walls and the corolla. Anthers light yellow.
Perianth Segments: Near spatulate, inner rather blunt and somewhat notched, light orange-red (Din 6164 5 E) about 2 cm long, 1/2 cm broad, outermost more pointed, all widely outspread.
Fruit: 5 mm diam., flattened globose, green-brown, with slit floral remains covering the pericarp.
Seed: About 1 1/4 mm long, J mm broad, 3/4 mm thick, sack-shaped with arched dorsal surface. Testa black, semi-dull, with minute tubercles running into each other, large basal hilum, not raised, brown.
Habitat: Narvaez, Prov. O’Connor, Dept. Tarija, Bolivia—rare.
Systematics: Belongs to subgenus Aylostera and is related to Rebutia albipilosa Ritter.
Holotype: This species was discovered by me in April 1958 and has my number FR 753.