3550 



ZYGOCACTUS 



ZYGOPETALUM 



4055. Zygocactus truncatus. ( X h) 



truncatus, Schum. (Epiphyllum trunc&tum, Haw.). 

 CRAB CACTUS. CHRISTMAS CACTUS. Fig. 4055. Sts. 

 much branched and hanging in large bunches from the 

 trees; joints obovate to oblong, with strongly truncate 

 apex, l%-2 in. long by about %-l in. broad, bright 

 green, margins 'coarsely serrate, with 1-3 large, acute 



teeth on each 

 side, the 2 upper 

 ones forming 

 more or less in- 

 curved horns on 

 either side_ of 

 the truncation : 

 areoles bearing 

 a few short yel- 

 lowish or dark- 

 colored bristles, 

 or sometimes 

 none: fls. hori- 

 zontal, growing 

 from the trun- 

 cated end of the 

 younger joints, 

 strongly irreg- 

 ular, 2 J4-3M in. 

 long, hi various 

 shades of red: 

 fr. pear-shaped, 

 red, about %in. 

 diam. Brazil. 

 B.M. 2562, G.C. III. 19:9. Most of the forms in cult, 

 are hybrids between this species and some other of the 

 genus or with allies of Cereus. A common basket- and 

 rafter-plant. 



For Epiphyttum Russettianum and E. Gsertneri, see Schlum- 

 bergera. J. N. ROSE. 



ZYGOCOLAX (compounded from Colax and Zygo- 

 petalum). Orchidacese. Hybrids between the genera 

 Colax and Zygopetalum. Z. Amesianus, Hort. (Z. 

 brachypetalum x C. jugosus). Fls. larger than the 

 latter parent; sepals and petals clear green, heavily 

 marked with dark purple; midlobe of Up heart-shaped, 

 white, with interrupted radiating lines of violet-blue. 

 Z. Chdrksworthii, Hort. (Z. Perrenoudii x C. jugosus). 

 Fls. dark green; sepals and petals closely marked with 

 purplish chocolate; lip violet with a white margin. 

 Z. leopardinus (Z. maxillare x C. jugosus). Fls. about 

 2 in. across; sepals and petals whitish, spotted and 

 marked with brown-purple; lip 3-lobed, side lobes 

 indigo-blue, midlobe same color but mottled with 

 white. Z. Vdtchii, Rolfe (Z. crinitum x C. jugosus). 

 Fls. about 3 in. across; sepals and petals light yellow- 

 green, spotted and blotched with brown-purple; lip 

 whitish with radiating lines of violet-purple. B.M. 

 7980. Gn.W. 20:89. J.H. III. 57:243. Z. Wigani- 

 anus, Hort. (Z. intermedium x C. jugosus). Similar 

 to the former in habit: fls. slightly larger; sepals and 

 petals pale green, barred with light brown; lip white 

 with violet lines. G.M. 43:121. Var. superbus, Hort., 

 has sepals and petals broad and rounded at the tips, 

 heavily barred and marbled with very dark purple; 

 lip flattish, extending horizontally, white heavily 

 marked with violet. G.C. III. 31:156. G.M. 45:142. 

 Z. woodlandense, Hort. (Z. maxillare var. Gautieri 

 x C. jugosus). F. TRACY HUBBARD. 



ZYGONISIA (compounded from Aganisia and 

 Zygopetalum) . Orchidaceae. Hybrids between the 

 genera Aganisia and Zygopetalum. Z. Rolfeana, 

 Hort. (Z. maxillare var. Gautieri x A. lepida). In 

 general appearance like the latter parent; its fls. 

 cream-white, blotched with violet. G.C. III. 32:30. 

 F.S.R. 3:176. Z. Sdnderi, Hort. (A. lepida x Z. sp.), 

 has cream-white fls. heavily blotched with violet. 

 These hybrids are not much known. 



ZYGOPETALUM (name referring to the united 

 flower parts). Orchidacese. Mostly epiphytic orchids 

 of easy culture. 



Plants with numerous distichous Ivs. sheathing a 

 short st. which usually becomes thickened into a 

 pseudobulb : Ivs. membranaceous, venose or plicate : fls. 

 solitary or in racemes, showy; sepals and petals nearly 

 alike in form and color, often united to each other at the 

 base, the lateral sepals forming a mentum with the foot 

 of the column; labellum with the lateral lobes scarcely 

 prominent, middle lobe broad and plane, spreading, or 

 recurved at the apex, with a prominent fleshy crest on 

 the disk; column incurved, wingless or with small wings; 

 pollinia 4, not appendiculate. 



The Z. Mackaii group grow well under pot culture. 

 One or two species with creeping rhizomes, like Z. 

 maxillare, thrive best on sections of tree fern, osmunda 

 rhizome, or hi baskets. A good compost consists of 

 equal parts of chopped sod, peat-fiber and sphagnum 

 moss, well mixed and interspersed with pieces of rough 

 charcoal, about one-half of the pot space being devoted 

 to clean drainage material. After distributing the roots, 

 the compost should be worked in carefully but not too 

 firmly about them, leaving the base of the plant even 

 with, or just above, the rim of the pot. Repotting should 

 be done when the plants show new root-action. The 

 temperature should range about 60 F. by night and 65 

 to 70 by day in winter, and in summer as low as pos- 

 sible, with free ventilation during inclement weather. A 

 cool, light location in the cattleya department is favora- 

 ble. The compost should be kept in a moist condition 

 at all times. The plants are propagated by cutting 

 through the rhizome between the old pseudobulbs at a 

 good eye, potting up the parts and removing them to a 

 rather higher temperature until they start into new 

 growth. (Robt. M. Gray.) 



A. Anther long-rostrate. 



rostratum, Hook. Pseudobulbs oblong, compressed: 

 Ivs. lanceolate, 5 in. long: scapes 4 in. long, bearing 

 1-3 fls.: sepals and petals linear-lanceolate, greenish 

 brown, wavy, 2-3 in. long; labellum about as long as 

 the petals, subrotund, with reflexed margins, pure white 

 with few radiating lines near the base; column-wings 

 rounded, sharply serrate on the upper margin; anther 

 with a long beak surmounting the column. May, June, 

 Oct. Guiana. B.M. 2819. J.H. III. 28:7. A.F. 6:633. 



AA. Anther not rostrate. 



B. Petals spotted or blotched. 



c, Labellum glabrous. 



Mdckaii, Hook. Fig. 4056. Pseudobulbs large, 

 ovate: Ivs. many, linear-lanceolate, 1 ft. long: scape 18 

 in. long, bearing 5 or 6 large fls.: sepals and petals 

 dingy yellowish green, with blotches of purple on the 

 inside, lanceolate, acute, erect, spreading, all united 

 toward the base; labellum large, rounded, emarginate, 

 white with radiating vein-like deep blue lines, glabrous. 

 Brazil. B.M. 2748. B.R. 1433 (as Eulophia Mack- 

 aiana). P.M. 3:97. L.B.C. 17:1664. J.H. III. 33:295. 

 G.M. 53:1037. This is distinguished from Z. inter- 

 medium and Z. crinitum by its smooth labellum and nar- 

 rower Ivs. Vars. superbum, grandiflprum, majus are 

 also advertised. Var. Charlesworthii, Hort. Sepals 

 and petals emerald-green, without purple markings. 

 G.C. III. 51:83. 



Gautieri, Lem. Pseudobulbs oblong-sulcate, 4 hi. 

 high: scape 2-3-fld.: fls. 3 in. across; sepals and petals 

 green blotched with brown; labellum broadly reniform, 

 deep purple at the base, white in front, sometimes 

 nearly all deep purple with a darker crest. Autumn. 

 Brazil. I.H. 14:535. Gn. 49:118. The Ivs. are fas- 

 ciculate, narrowly oblong, keeled, 12-16 in. long: infl. 

 shorter than the Ivs. 



