Phytologia (Aug 2004) 86(2) 57 



Perennial herb from a fleshy taproot, succulent, poikylohydric, body 

 swelling immediately after rainfall. Stem solitary, caespitose with age 

 dividing dichotomously, laterally, or sprouting from rootstock exposed 

 to light, individual stems obpyriform when hydrated or flattened disc 

 shaped with conspicuous central cuplike depression when dessicated, 

 lacking ribs or pronounced tubercles, 1-1.5 (2.5) cm in diameter, grey- 

 green to dark green depending on environmental conditions. Stems with 

 a single epidermal layer, external cell walls barely thickened, lacking 

 epicuticular wax coating. Stomata restricted to areolar pits, overall 

 density much less than 1 per ram-. Areoles spirally arranged, circular 

 in face view, tomentose, unarmed. Flowers solitary, subapical arising 

 from the depressed felted crown, usually hermaphroditic, sometimes 

 dichogamous or even unisexual (trimonoecism), opening only in full 

 sun. Flowers turbinate to funnelform, 0.6-1.5 cm long, sometimes with 

 nectary- glands. Pericarpel sculptured with podaria tipped by small 

 lanceolate to triangular scales, or with only a few scales and essentially 

 glabrous on the lower part, bearing whitish to gray wooly hairs in the axils. 

 Perianth segments sequentially intergrading in form and color, reflexed. 

 Outermost tepals acuminate, olive-brown. Inner tepals narrowly ovate, 

 rounded apically, white to pale yellowish-white. Androecium in more than 

 two series, equivalent in length. Stamen sometimes wanting, filaments 

 whitish, anthers yellow to gold-yellow. Pollen subspherical, tricolpate, 

 with smooth exine. Stigma and style sometimes wanting, whitish. 

 Stigmatic branches lanceolate, tapering distally, papillose only on the 

 inner surfaces and margins. Fruit a juicy berry, spherical to ovoid or 

 pyriform, about 0.5 cm, wall irregularly sculptured with podaria bearing 

 large scales, and axillary hair in small bundles, without bristles, brown, 

 side splitting when ripe then disintegrating over time to release the seed. 

 Seeds globose, small, 0.5 mm in diameter, testa minutely papillose, 

 shiny red-brown, with large ivory hilum. Chromosome number: n = 33 

 (Ross, 1981). 



Blossfeldia lacks xeromorphic stem features of other globular cacti 

 (Barthlott and Porembski 1996) and its globose ornamented and arillate 

 seed is distinctive in the family. Equally distinctive is the restriction of 

 stomata to areolar crypts and extremely low density of stomata on the 



