Xerophyte

Central Spines

Usually absent.

Seeds

1.2-1.2 mm, matt black.

Description

Gymnocalycium platense is a small, usually unbranched, cactus species, depressed, half-hidden in the earth. It will flower when 3-5 cm in diameter. The flowers with long floral tube, open wide in sunlight, and are commonly white with a reddish reddish throat and a hint of dark shading at the tips of the tepals. This is a delightful plant and well worth growing.

Note

Gymnocalycium platense is often confused commercially with unrelated species of the Gymnocalycium bodenbenderianumSN|14405]]SN|14405]] group and Gymnocalycium leptacanthum. Plants sold under this name but having flowers with red throat and glossy brown seeds are probably Gymnocalycium quelianum or a related species.

Flowers

Several together on the crown, diurnal, scentless, 3 to 6.5 cm in length and 4-6.5 cm across, openong wide in sunlight. Tube and ovary dull bluish green bearing a few broad, short, rounded scales, these more or less purplish on the edge. Outer perianth-segments white with a broad green or pinkish stripe down the center. Inner perianth segments pure white with a hint of dark shading at the tips of the tepals. Throat broad, white, reddish or purple within. Filaments numerous, scattered over the throat. Style short and thick, 2 cm long, stigma-lobes cream-coloured. Ovary oblong.

Blooming Season

This plant blooms in early summer when it is only 3-4 cm.

Ribs

8-18, usually 13, broad and low, with strong cross-furrows, with distinct rounded tubercles. Tubercles with a horizontal or ascending chin-like projection.

Stem

Solitary, flattened globose to globose, green, dull bluish green, olive green, or purple or bronzed never greyish (rather variable in colour in cultivation depending on growing conditions), 8-10 cm high, 4-10 cm in width.

Radial Spines

3 to 7, thin, needle-like, subulate, rigid, more or less flattened against the stem surface, base swollen pale brown-red, greyish-purple, grey or blackish, with whitish tips, 5-15 mm long.

Fruits

The ripened ovary is pink, almost spherical, 1-2.5 cm long, 1-2 cm in width, and dehisces (splits) down its length.

Areoles

Deep-set, when young white-felted.