DORSTENIA 



DOUGLASIA 



1067 



DORSTENIA (Theodor Dorsten, professor of medi- 

 cine at Marburg, died 1539). Mordcese. About 50 tropi- 

 cal herbs or small shrubs, remarkable for the dilated 

 receptacle in which the unisexual fls. are borne, being 

 imbedded in the surface. Both staminate and pistillate 

 fls. are without perianth; stamens 1-4; ovary 1-loculed; 

 stigma 2-lobed. Dorstenias are easily grown in warm 

 shady glasshouses. The plants are not in the American 

 trade, but they are often grown in botanical establish- 

 ments to illustrate morphology. The fig is a hollow 

 receptacle formed of the axis of the fl. -cluster; the dor- 

 stenia bears a flattened or cup-like receptacle, and is 

 an intermediate stage between the fig and other plants. 

 One of the common species is D. Contrajerva, Linn. 

 (Fig. 1343), which is native to Trop. Amer. : fls. on a 

 scape: Ivs. round-cordate, palmately lobed or parted, 

 the segms. ovate or oblong and more or less toothed: 

 receptacle irregularly rectangular, peltate: 

 rhizome cylindric, nodose. Mex., W. Indies, 

 Venezuela, Colombia. L. H. B. 



DORYALIS: Aberia. 



DORYANTHES (Greek, spear-flower; the 

 flowering stem 8 to 25 feet high, crowned by a 

 spike of flowers 3 feet high). Amaryllidacese. 

 Great desert plants from Australia, with 100 

 or more leaves 6 feet long when full grown, 

 being impressive for large conservatories, or 

 for open ground in the South, where they will 

 stand slight frost. 



The representative in Austral, of the Ameri- 

 can Furcrsea and Agave: Ivs. 

 in a dense basal rosette, those 

 on the st. much reduced: fls. 

 large, bright red (often replaced 

 by bulblets), in a large thyrse- 

 like or panicled infl.; perianth 

 with little or no tube, the 

 segms. long and falcate; sta- 

 mens 6, attached at base of 

 perianth, the filaments filiform: 

 fr. a turbinate caps., 3-valyed. 

 Three or 4 species. Little 

 known under glass, as they re- 

 quire too much room. A plant 

 of D. Palmeri remained at 

 Kew 16 years before flowering. 

 Plants of doryanthes are prop. 

 by suckers, which are pro- 

 duced only after flowering. 

 The process is very slow. The 

 young plants must be repotted 

 for several years until they 

 have attained a large size. 

 They are said to do best in a 

 compost of loam and leaf -mold 

 in equal parts. 



excelsa, Correa. SPEAR-LILY. Lvs. sword-shaped, 

 not ribbed, smooth, entire, with a very narrow carti- 



1343. Dorstenia Contrajerva. ( X H) 



Ivs. 9 ft. long, over 8 in. wide: fls. rich crimson, 4 in. long. It yields 

 a good fiber. Gn. 44, p. 69. G.C. III. 45:383. 



WILHELM MILLER. 

 L. H. B.f 



DORYOPTERIS (Greek, lance-fern). Polypodiacese. 

 Small pot ferns with oddly pretty leaves. 



Leaves with continuous marginal sori and copiously 

 anastomosing veins. About 20 species, in warm coun- 

 tries. Sometimes joined to Pteris, which see for cul- 

 ture. Not to be confused with Dryopteris. 



palmata, J. Smith. Lvs. 4-9 in. each way, with 5 or 

 more triangular lobes or the fertile still more divided; 

 ribs black. W. Indies to Brazil. Sometimes considered 

 to be a variety of D. pedata, Fee. 



nobilis, J. Smith. Larger: Ivs. sometimes 1 ft. long, 

 pedately bipinnatifid; ribs chestnut. S. Brazil. 



D. dectpiens, with Ivs. resembling a geranium If., 3-6 in. 

 each way, is sometimes cult., as is D. dfcora, with more 

 divided Ivs. Both are natives of the Hawaiian Isls. 



L. M. UNDERWOOD. 



DOSSINIA (E. P. Dossin, Belgian botanist, 

 1777-1852) . Orchidacese. One species of terrestrial 

 orchids, allied to Anoactochilus, but lacking the 

 bearded fringe on the lower part of the labellum. 

 This species may possibly be cult, by a few 

 amateurs who are skilled in the cult, of dwarf 

 warmhouse foliage plants. 



D. marmorata, C. Morr. (Anoectochilus Lowei, Hort.). 

 Lvs. golden-veined or marbled, 4-5 in. long, elliptic: scape 

 pubescent, 10 in. high; spike 5 in. long, with many white, 

 pubescent fls. Java. F.S. 4:370. There is a stronger-grow- 

 ing var., with foliage better colored. 



DOUGLASIA (after David 

 Douglas, the Scotch botanist, 

 who explored California, Ore- 

 gon and British Columbia in 

 1823 and 1829). Incl. Aretia. 

 Primulacese. Low tufted per- 

 ennial herbs, one of which is 

 used in alpine gardening. 



The genus is closely allied to 

 Androsace and Primula, but in 

 those two genera the Ivs. come 

 from the root, while Douglasia 

 has branches, though very 

 short ones, which are densely 

 clothed with Ivs. Douglasia 

 has a corolla-tube equaling or 

 exceeding the calyx, somewhat 

 inflated toward the top, with 5 

 scales or crests beneath the 

 sinuses; calyx 5-lobed, persist- 

 ent; stamens 5, included; ovary 

 5-ovuled : fr. a turbinate 1- or 

 2-seeded caps. Seven or 8 

 species in mountains of Eu., 

 and W. N. Amer., considered to 

 be 6 by Pax & Knuth in Engler'a 

 Pflanzenreich, hft. 22 (1905). The fls. are yellow in D. 

 Vitaliana, which is the cult, species, but otherwise 



laginous margin, lower ones recurved, others erect: rose-purple. The plants require the treatment accorded 



scape clothed with lanceolate Ivs., which sheath the 

 et. at their base; fls. in a globular head, deep crimson or 

 maroon inside and out (there is a white-fld. form). 

 B.M. 1685. R.H. 1865, pp. 466, 471; 1891, p. 548. 

 G.C. II. 11:339. Gn.W. 16:681. G.W. 9, p. 521. 

 H.F. II. 7:136. 



Palmeri, W. Hill. Even more gigantic than D. 

 excelsa: Ivs. longer and broader, slightly ribbed and a 

 longer brown point: fls. in a thyrsoid panicle, bright 

 scarlet outside, whitish within. B.M. 6665. F.S. 

 20:2097. R.H. 1891:548. G.C. II. 17:409. G.W. 12, 

 p. 222. New shoots are said to be produced at the base, 

 which bloom in one or more years. 



D. Guilfdylei, F. M. Bailey, QUEENSLAND-LILT, is a large and 

 fine species from N. Queensland, perhaps a form of D. Palmeri: 



68 



to other alpines; see Alpine Plants, Vol. I. 



Vitaliana, Hook. f. (Primula Vitaliana, Linn. 

 Androsace Vitaliana, Reichb. Aretia Vitaliana, Lodd. 

 Gregbria Vitaliana, Duby). Height 2 in.: sts. numer- 

 ous, prostrate, somewhat woody: branches denuded of 

 Ivs. at the base, but at the tips clothed with overlapping 

 linear entire pilose Ivs.: fls. nearly stalkless, solitary or 

 2 or 3, yellow, rather large; corolla-tube 2 or 3 times 

 longer than the calyx, the lobes ovate-lanceolate, 

 obtuse. Alps, Pyrenees. L.B.C. 2:166. 



Some of the American douglasias, all with rose or purple fls., 

 are sometimes listed by foreign specialists in alpines. D. drctica, 

 Hook. Glabrous: Ivs. ciliate with short and simple hairs, apex 

 obtuse: fl. 1 on a scape; corolla-tube about equaling calyx: plant 

 loosely cespitose. High arctic Amer. D. dentAta, Wats. Like D. 

 nivalis and by some considered to be a form of it, but coarser and 



