DICHORISANDRA 



DICKSONIA 



1003 



the base, sessile, glabrous, about 6 in. long, 3-4 in. wide, 

 with a short, sharp, rather abrupt point: st. unbranched, 

 robust, spotted: raceme short, densely thyrsoid; sepals 

 white or greenish. Gt. 1868:593. F.S. 16:1711. Its 

 chief beauty is the mosaic appearance of the foliage, 

 due to numberless short transverse whitish lines, 

 which do not pass by the longitudinal veins of the If. 

 The under side of the Ivs. is a rich purplish color. Var. 

 gigantea, Hort., a large form, has been offered. 



Var. undata, Miller (D. undata, C. Koch & land.). 

 Foliage without any mosaic appearance, the variega- 

 tion being entirely longitudinal. Each parallel vein 



1259. Dicentra Cucullaria. Dutchman's Breeches. 



lies in the middle of a long, whitish band extending the 

 full length of the If. F.S. 17:1763. G.W. 3, p. 159. 



D. acaiilis, Cogn. Stemless: Ivs. in a rosette, almost sessile, 

 narrowly oblong, wavy, acutish, short-cuneate at the base, sparsely 

 pilose on both sides: panicles terminal, sessile, much shorter than 

 the Ivs. Brazil. I. H. 41:19. Handsomely variegated with count- 

 less short longitudinal lines. D. dlbo-marginata, Lind. St. 3-4 

 ft.: Ivs. lanceolate, acuminate, attenuate to base, glabrous: raceme 

 peduncled, 2 in. long, dense; petals dark blue, white at base; sepals 

 white. Brazil. G.W. 4, p. 307. D. angustifdlia, Lind. & Rod 

 St. purple, spotted green: Ivs. oblong-lanceolate, sessile, glabrous 

 roundish at the base, acute, about 6 in. long, 2 in. wide at the middle 

 purple below, marked above with short transverse white lines 

 Ecuador. I. H. 39:158. D. leucophthdlmos, Hook., differs in hav 

 ing radical infl., its fls. lying fiat on the ground. Lvs. elliptic, acumi 

 nate, green on both sides: fls. blue, with a white eye; stamens 6 

 Brazil. B.M. 4733. J.F. 4:428. D. ovalifdlia, Presl. Lvs. oval 

 sessile, acuminate, glabrous, the upper ones oblong-lanceolate 

 panicle wide-branching. Nicaragua to Colombia. D. oxyp&ala 

 Hook., is instantly recognized by its acute petals, which are purple 

 Lvs. green on both sides. Brazil. B.M. 2721. D. picta, Lodd., has 

 narrower petals than usual, with a white spot at the base, but is 

 told from all others here described by the irregular blotches of 

 purple on the upper side of the Ivs. The purple is the same color 

 as that on the under surface. Brazil (?}. B.M 4760. L.B.C. 

 17:1667. D. Regina, Hort. = Tradescantia Reginae, Lind. & 

 Rod., intro. about 20 years ago by a firm of Continental Eu. 

 D. Sanndersii, Hook., differs from all others here described in 

 the extreme density of its head-like infl. Lvs. green on both 

 sides, lanceolate: sepals white, tinged blue. Brazil. B.M. 6165. 

 D. Si&bertii, Hort. A little-known plant with white midrib and 

 margins; probably a form of D. ovalifolia. D. <%sidna=Palisota. 



WILHELM MILLER. 

 L. H. B.f 



DICHROA (Greek, dis, two, and chros, color). Syn. 

 Adamia. Saxifragacese. Rare greenhouse shrub in 

 habit resembling a Hydrangea, with violet-blue fls. in 

 a pyramidal panicle a foot across, and handsome blue 

 berries. Lvs. persistent, opposite, stalked, narrow, 

 tapering both ways, serrate: panicles terminal, many- 

 fld.; fls. blue, lilac, or violet; petals 5 or 6, valvate; 

 styles 3-5, club-shaped: seeds numerous, small. The 



64 



genus has only 1 species, in the Himalayas, Malaya, 

 and China. It is sometimes considered to be bitypic, 

 but the other species, D. pubescens, Miq., is considered 

 by Reorders (Exkursionoflora von Java) to be probably 

 a true Hydrangea. 



febrifuga, Lour. (Adamia versicolor, Fortune. Cyanl- 

 tis sylvdtica, Reinw.). Later writers also include 

 Adamia cyanea, Wall., which Lindley distinguished by 

 its smaller Ivs. and fls., 5 petals, and 10 stamens, while 

 A. versicolor had 7, or sometimes 6 petals, and 20 

 stamens. Plants may still be cult, under the name 

 of A. cyanea, but it cannot be stated here how distinct 

 they are for horticultural purposes. A somewhat 

 virgate shrub 5-9 ft. tall, with lanceolate or obovate- 

 lanceolate Ivs. to 8 in. long, glabrous except on the 

 nerves; petals less than J^in. long. Clarke states that 

 the Chinese varieties have larger fls. than the Indian 

 forms. Occurs in the temperate Himalayas from 5,000- 

 8,000ft. B.M. 3046. P.M. 16:322. 



WILHELM MILLER. 



DICHROPHfLLUM: Euphorbia. L> H> B '^ 



DICHROSTACHYS (two-colored spikes). Legu- 

 minosse. Stiff shrubs, with bipinnate Ivs. and small 

 leathery Ifts. and very small polygamous fls. in spikes, 

 sometimes mentioned as useful for cult, in warmhouses. 

 The species are few, in Trop. Asia, Afr., and Austral. 

 Fls. in the upper part of the spike perfect, those of the 

 lower part bearing 10 long filiform staminodia; corolla 

 not papilionaceous, comprising 5 strap-shaped petals 

 that are more or less united at base; stamens 10 in the 

 perfect fls., free, slightly exserted: pod narrow, com- 

 pressed, mostly or nearly indehiscent. D. platycarpa, 

 Welw., is or has been in cult.: a slender spiny tree, 

 10-15 ft. high: pinnae 10^18 pairs, the Ifts. 1-2 lines 

 long and very narrow: spikes usually shorter than the 

 Ivs.: pod twisted, 2-4 in. long, about 1 in. broad. 

 Guinea. D. nutans, Benth. (Cailliea Dichrdstachys, 

 Guill. & Perr.), has been intro. in S. Calif.: spiny, 

 much contorted shrub or small tree: Ivs. glabrous or 

 pubescent, acacia-like; pinnae 5-10 pairs; Ifts. 10-20 or 

 more pairs, sessile, linear or linear-oblong, rarely as 

 long as ^in.: fls. in dense axillary twin or solitary 

 spikes, the upper ones sulfur-yellow and the lower ones 

 rosy lilac: pod twisted, J^in. or less broad. Cent. Afr. 



L. H. B. 



DICKSONIA (named for James Dickson, an English 

 botanist, 1738-1822). Cyathedcex. Tree ferns of 

 greenhouses. 



Plants with a distinctly 2-valved inferior indusium, 

 the outer valve formed by the apex of the If.-segm. 

 A small genus, mostly of the southern hemisphere. 

 For D. pilosiuscula, D. punctilobula and D. Smithii, 

 see Dennstsedtia. For D. Schiedei and D. regalis, see 

 Cibotium. These are only two of several confusions of 

 species which have been called Dicksonia, but really 

 belong in other genera. Modern fern students are now 

 reaching the conclusion that Dicksonia is not only very 

 distinct from the genus Cyathea and its relatives, but 

 belongs in a distinct family. 



Dicksonias are amongst the most important tree 

 ferns, both for their beauty and because of their relative 

 hardiness. In their native countries some of them are 

 occasionally weighted with snow, and D. antarctica has 

 to endure frosts. They can be grown in coolhouses, 

 and should be tried southward outdoors in sheltered 

 places. Their trunks are more fibrous than those of 

 most tree ferns, and hence more retentive of moisture, 

 so that they need less care. A good trunk produces 

 thirty to forty fronds a year, and retains them until 

 the next set is matured, unless the trees suffer for mois- 

 ture in winter. Although they rest in winter, the fronds 

 soon shrivel up if the trunks are allowed to get too dry. 

 Dicksonias should have their trunks thoroughly watered 

 twice a day during the growing season. These waterings 



