260 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
ZYGOCACTUS Schum. in Mart. Fl. Bras. 42: 223. 1890. 
Stems much branched, flattened, divided int» short joints; flowers terminal, irreg- 
ular, zygomorphic; ovary terete, smooth and bractless, gradually broadening from 
the base, bearing minute bracts above; sepals ovate; corolla tube abruptly bent just 
above the ovary, bearing scattered petals along its sides and ending in a serrate mouth; 
stamens slender, white, arranged in two clusters; outer stamens borne along the 
inside of the corolla tube from near the base to near the middle; inner clusters of 
stamens about 20 (Schumann says 10) arising from the center and forming a short tube 
about the base of the style with an inner, deflexed, toothed membrane, the upper part 
free; style purple, slender, as long as the stamens; stigma single, clavate, solid, purple. 
Type species, Epiphyllum truncatum Haw. 
Zygocactus altensteinii (Pfeiff.) Schum. in Mart. Fl. Bras. 4?: 225. 1890. 
Epiphyllum altensteinii Pieiff. Enum. Cact. 128. 1837. 
Type Locauity: In Brazil. 
DistTRIBuTION: Brazil. 
ItLustRations: Pfeiff. & Otto, Abbild. Beschr. Cact. 1: pl. 28, as Epiphylium 
altensteinii. 
Zygocactus delicatus (N. E. Brown) Britt. & Rose. 
Epiphyllum delicatum N. E. Brown, Gard. Chron. III. 32: 411. 1902. 
Epiphyllum delicatulum Schum. Monatsschr. Kakteenk. 13: 9. 1903. 
Type Locauity: In Brazil. 
Distrrmvtion: Brazil. 
Intustrations: Gard. Chron. III. 82: f. 140. Schum. Gesamtb. Kakt. Nachtr. 
J. 9; Monatsschr. Kakteenk. 18: 7—both as Epiphyllum delicatulum. 
Zygocactus truncatus (Haw.) Schum. in Mart. Fl. Bras. 4?: 224.1890. Pare 80. 
Epiphyllum truncatum Haw. Suppl. Pl. Succ. 85. 1819. 
Cactus truncatus Link, Enum, Pl. 2: 24. 1822. 
Cereus truncatus A. DC. Prodr. 8: 470. 1828. 
Type tocauity: In Brazil. 
DistriBuTion: Brazil. 
ILLusTRaTiIoNs: Mart. FI. Bras. 4*: pl. 46. Curtis’s Bot. Mag. 52: pl. 2562; Ed- 
wards’s Bot. Reg. 9: pl. 696; Reichenb. Fl. Exot. pl. 825—all as Cactus truncatus. 
Blihende Kakt. pl. 25; Cact. Journ. 1: 34, 114; Cycl. Amer. Hort. Bailey 2: 
J. 765; Engl. & Prantl, Pflanzenfam. 3%: /. 61. A, B, C; Schum. Gesamtb. Kakt. 
J. 9, 43; Hort. Univ. 7: facing p. 132; Karst. Deutsch. Fl. 887. f. 3; Forst. Handb. 
Cact. ed. 2. 129. f. 5; Riimpl. Sukkulenten /. 87—all as Epiphyllum truncatum. 
EXPLANATION OF PLATE 80.—Flowering branch of a greenhouse specimen. Natural size. 
SCHLUMBERGERA Lem. Rev. Hort. IV. 7: 253. 1858. 
Stems much branched, flattened; plants similar in habit to Zygocactus; flower 
regular, its tube very short. 
The taxonomic history of the two species here recognized is interesting. S. gaertneri 
was first supposed to be conspecific with S. russelliana and was regarded as a variety 
of that species by Regel. In 1890 Schumann considered them distinct species, but 
congeneric, while in 1899 he referred them to different genera. Both species are 
probably from Brazil. 
Type species, Schlumbergera epiphylloides Lem. 
Schlumbergera gaertneri (Regel) Britt. & Rose. 
Epiphyllum russellianum gaertneri Regel, Gartenflora 88: 323. 1884. 
Epiphyllum gaertnerit Schum. in Mart. Fl. Bras. 42: 218. 1890. 
Phyllocactus gaertneri Schum. in Engl. & Prantl, Pflanzenfam. 3°: 218. 1894. 
