Sub-tribe 3. Echinocereanae
Culture: A well-drained but rich soil with liberal water in growing season. If in outdoor location, as is possible in the districts of moderate temperatures, a partly shaded spot should be selected.
Desirable species: Acanthocalycium formosum (Pfeiff.) Bckbg. has not flowered in cultivation in the United States, but is treasured for its attractive form. A. chionanthum (Speg.) and A. thionanthum (Speg.) are obtainable and desirable. A. spiniflorum (Schum.) and other species are free bloomers and all species are equally attractive.
Recent New Species Since Br. & R.
A. hyalacanthum (Speg.) Bckbg. (Lobivia Speg. 1925, Echinopsis Werd.). Cylindrical with 12 to 16 ribs; the 11 to 16 radial spines and the 1 to 4 central spines reddish or white, later transparent; the flowers
Genus 3. Rebutia Schumann, 1895.
Syn.: Mediolobivia (in part) Bckbg., 1935.
Syn.: Aylostera Speg.
Small globose to short cylindrical plants (Pl.
11: Fig. 3), usually forming groups of several to many heads, definite ribs are lacking; the areoles surmounting small tubercles; flowers arising from the base or side of the plant are small, red,

orange or yellow and are funnel-shaped; in some species the pistil is enlarged to completely fill the tube but in others it is smaller; ovary bearing small scales which are without content in some species but bear hairs in their axils in other species; fruit small, red, bearing scales which some
are from the side of the plant, 4 to 5 inches long, golden yellow.
A. Klimpelianum (Weidl. & Werd.) Bckbg. (Echinopsis Weidl. and Werd. 1928, Lobivia Berger). Globose with a depressed top; about 19 notched ribs, not spiralled; the 6 to 10 radial and 2 central spines straight, somewhat awl-shaped, brown or black; the white flowers are only about 2 inches long, from the side of the plant.
A. oreopepon (Speg.) Bckbg. (Lobivia Speg. 1925, Echinopsis Werd.). Globose with 18 or 20 notchedribs; the 10 to 15 radial spines and the 1 to 5 central spines are all alike, slender and flexible, red to yellow, later gray; flowers from near the top of the plant, golden yellow.
A. Peitscherianum Bckbg. Globose with 17 ribs; 7 to 9 radial and 1 central spine; the small lavender flowers only about 2½ inches long.
A. violaceum (Werd.) Bckbg. (Echinopsis Werd. 1931). Closely resembling A. spiniflorum and considered by Dr. Hosseus as synonymous with that species.
times subtend hairs. The, genus intergrades with Lobivia and the dividing point is arbitrary. Efforts by some classifiers to define a definite point of departure has resulted in the erection of new genera which still leaves the matter uncertain. Here we refer the newly proposed genera Mediolobivia and Aylostera.
The plants with pistil enlarged were assigned to Aylostera with the notation, “pistil united to tube” but this is not true, the pistil being entirely separate from the tube but so enlarged as to completely fill it.
Habitat: Argentina and Bolivia.
Culture: Rebutias are most frequently seen as grafted plants with little or no reason, as they do well on their own roots in a light, fairly rich soil in a partly shaded location, or potted and the pots plunged in sand outdoors in the growing season and taken in for the colder periods.
Desirability: The highly colored flowers very freely produced, and the minimum of space required, makes the genus a very acceptable one.
Desirable species: Numerous species in seedling form are offered. Rebutia Marsoneri Werd.,
R. minuscula Schum., R. elegans Bckbg., and R. violaciflora Bckbg., are recommended, but any species is desirable.