202 THE CACTACEAE. 
KEY TO SPECIES. 
Slender with linear lateral branches, their margins slightly toothed; style and stamens about length of ; 
perianth-segments. .... 0.0... eee eee eee . 1. D. biformis 
Spreading with oblanceolate lateral branches, their margins crenate; style and stamens long-exserted.. 2. D. etchlamiu 
1. Disocactus biformis Lindley in Edwards’s Bot. Reg. 31: pl. 9. 1845. 
Cereus biformis Lindley in Edwards’s Bot. Reg. 29: Misc. 51. 1843. 
Disisocactus biformis Kunze, Bot. Zeit. 3: 533. 1845. 
Phyllocactus biformis Labouret, Monogr. Cact. 418. 1853. 
Epiphyllum biforme G. Don in Loudon, Encycl. Pl. ed. 3. 1378. 1855. 
Plant 2 dm. long or longer; branches linear, 5 to 8 cm. long, 1 to 2 cm. broad, with serrate 
margins; flower-bud elongated, curved upward, pointed; tube of the flower about 1 cm. long, the 
segments 8 (rarely 9), magenta, about 3 cm. long, the outer 4 or 5 spreading or curved backward, 
linear, the inner 3 or 4 broader and more erect; stamens 10 to 12, slightly exserted, borne in 2 series 
at top of tube; style slender, purple; stigma-lobes 4, white; ovary short-oblong, green, somewhat 
tubercled, with a few areoles subtended by small ovate scales; fruit ovoid, 1.5 cm. long, turgid, 
wine-colored. 
Type locality: Honduras. The species described from a garden specimen, introduced 
into England in 1839. 
Fic. 205.—Disocactus eichlamii. 
Distribution: Honduras and Guatemala. 
We have had this plant under observation for a number of years. It is rather a shy 
bloomer with us, although we get one or two flowers each spring; the flowers open in the 
night or early morning and remain open all day; they begin to wither the second morning. 
The perianth-segments are more widely spreading in the morning than in the afternoon. 
The flower is almost horizontal and the tube proper is about the length of the ovary. The 
fruit matures very slowly. In 1920 we had a plant flower in April, but the fruit did not 
mature until July 8. 
I llustrations: Forster, Handb. Cact. ed. 2. 876. f. 120; Riimpler, Sukkulenten f. 86, 
as Disisocactus biformis; Blithende Kakteen 1: pl. 54; Curtis’s Bot. Mag. ror: pl. 6156; 
Dict. Gard. Nicholson 3: f. 135; Monatsschr. Kakteenk. 9: 141; Watson, Cact. Cult. 50. 
f. 12, as Phyllocactus biformis; Loudon, Encycl. Pl. ed. 3. 1379. f. 19403, as Epiphyllum 
biforme; Edwards’s Bot. Reg. 31: pl. 9; Palmer, Cult. Cact. 175. 
Plate xxxul, figure 2, shows a branch of a fruiting plant sent to Dr Rose by 
Robert Lamb of Manchester, England, in 1912. F igure 203 shows the flower of the same 
plant; figure 204 is from a photograph of the same plant in flower. 
