This is a small growing and easy to to flower species with a naturally dark body and nicely contrasting bright yellow flowers.
Family: Cactaceae (Cactus Family)
Scientific name: Copiapoa tenuissima F.Ritter, (nom.. inval. Art. 37.1)
In: Taxon 12(1):29 1963
(First mentioned in Backeberg, Die Cact. 6: 3840, 1962 (as nom. nud.)
Origin: Northern Chile, Antofagasta
Habitat: Native to the coastal deserts on the steep mountain base among fragmented stones. The long tuberous root of this copiapoa is buried deeply in these soils which are very poor in organic matter. In the area where this plants grows there is very little rain but frequent coastal fog, which provides a significant part of their water needs. The common presence in habitat of plants with juvenile spination forms on old taproots is due to the frequent grazing damage inflicted by donkeys and Guanacos.
- Copiapoa hypogaea ssp tenuissima (Ritter ex Hunt) Hunt 2003
NOTE: As the original description is invalid, this is the actual basionym for the taxon.
Copiapoa humilis var. tenuissima (F. Ritter) G. J. Charles 1960 (n. val. publ.)
Conservation status: Listed in CITES appendix 2.
Small growing and easy to to flower has a naturally dark body with nicely contrasting bright yellow flowers.
Description: Single headed or slowly clumping, usually at or slightly below soil level.
Stems: Up to 5 cm in diameter, flattened to spherical, dull-green, dark olive green, to almost purplish-black. The stem is tubercled rather than ribbed stem and the slightly felted apex can be regarded as persistent juvenile characters, which can be explained by the need for the plant to multiply as early as possible, before they fall victim to the Guanacos.
Roots: Large tuberose connected to the stem by long slender neck. Seedlings naturally produce the huge tap root, starting from germination, i.e. before the plant stem becomes mature.
Ribs: 13-16 spiralling, 3-4 mm tall.
Areoles: White abundantly woolly.
Radial spines: Very thin (almost hairy), acicular, usually straight 8-14, 3-6 mm long, yellowish to blackish.
Central spines: 0-1 (-2) 4-10 mm long.
Flowers: Pretty, yellow diurnal, up to 2.5 cm long. Tepals up to 15 mm long 5-7 mm wide. Ovary with pubescent scales, floral tube 4-7 mm long. The flowers are supposedly to be sweet scented. (The hairy ovary and fruit are a link with Ritter's Pilocopiapoa solaris)
Blooming season: Spring and summer. In cultivation in the C. tenuissima are able to flower from immature stems at an early age (c. 2 years from germination) and set viable seed.
Fruit: Globose, green to maroon unusual for the genus by being woolly, a primitive characteristic.
Cultivation: Need full sun otherwise the bodies tended to elongate in cultivation, but should be protected from excessive heat and sun in summer, Require light watering, good drainage, and deep pot to accommodate tap root. . Keep warm and dry in winter to avoid rot. Frost tolerance 0°C
Propagation: Usually by seeds. Heads can be used as cuttings. They grow slowly at first until they develop the large tuberous root. Grafting is also used to speed growth rate and to create a back-up to plants in collection.