Frailea castanea Nitens Origin and Habitat: The plant is found from Southern Brazil to Northern Uruguay.
Altitude: It grows at elevations from 150 to 300 metres above sea level.
Habitat and Ecology: The cactus grows on rocky outcrops and stony fields in pampa grasslands. This species is not abundant in Brazil but is common and abundant in Uruguay; it is sparsely distributed where it occurs. The major threats to this species are grazing and cattle trampling, agriculture, forestry, fire and collection, but not in all of its range.
Frailea castanea Nitens Description: Frailea castanea (a.k.a. Frailea asterioides) is a very singular miniature plant, and one the of most fascinating cacti with a disk like, flattened to globose body.
Stem: It is diminutive in size and several remain solitary, never outgrowing 4-5 cm diameter. Stems are chocolate brown or dark reddish-green with 8-15 flat ribs.
Spines: 3-15 minute, short, black spider-like, appressed on the plant body and usually all bent downward.
Flower: Sulphur yellow, sometimes larger than the plant itself (4cm diameter). But don’t be disappointed when the easily produced buds fail to open. Fraileas are cleistogamous meaning that their flowers produce seed without even opening. Without the need for pollination, hence the buds rarely reach full bloom and remain closed. They will open only in great heat in the hottest, brightest, afternoon sun, if at all.
Fruits: Dry indehiscent that detach easily, pericarp membranous, fragile that break easily releasing the seed.
Seeds: Very big 3-3,5 mm wide. The seed is shaped strangely for a cactus, and is often described as “hat” or “boat” shaped with a prominent edge. That is a good description, for it is among the few cactus seeds that float! They are thought to be dispersed in habitat by floating away on runoff.
Remarks: This plant is short living (It does not live long – about 10-15 years).