GENUS 



GEONOMA 



1329 



GENUS, pi. GENERA (i. e., kind), is a term used in 

 natural history to designate a group of species. As with 

 species, so the genus is an indefinite conception, varying 

 with the author. The chief value of the conception is 

 its use in aiding us conveniently to arrange and name 

 plants and animals. The name of the genus is the first 

 of the two words in the name of the plant: thus, in 

 Brassica oleracea, Brassica designates the genus, and 

 oleracea the particular Brassica of which we are speak- 

 ing. It is difficult to trace the origin of the genus- 

 conception in natural history, but it is usually ascribed 

 to Konrad Gesner (Zurich, 1516-1565). L. H. B. 



GEODORUM (gift of the earth). Orchidacex. Orchids 

 of minor importance, E. Indies to Austral., with radi- 

 cal lanceolate or elliptical Ivs., tuberous bulb-like 

 rootstocks, and vari-colored fls. in a nodding spike 

 on the top of the scape; sepals and petals similar, lip 

 upright: terrestrial. Belongs in the same sub-group 

 or tribe as Cyrtopodium and Eulophia. In habit, they 

 somewhat resemble Phaius and 

 Eulophia, and require similar 

 treatment, with potting in fibrous 

 loam and peat. Apparently not 

 offered in this country, but some- 

 times grown abroad in collec- 

 tions. G. purpureum, R. Br., 

 from India: Hke a Bletia in 

 habit: Ivs. large: scape erect, 

 bearing a densely-fld. drooping 

 raceme; fls. small, white with purple 

 markings on the lip. G. fucatum, 

 Lindl., of Ceylon: 1 ft.: Ivs. oblong- 

 lanceolate and plicate, the scapes re- 

 curved at the apex: fl. with pink nar- 

 row sepals and ovate lip. B.R. 1687. 

 G. pictum, Lindl., from New. Holland, 

 grows 1-2 ft., with dull rose-purple 

 fls. shaded brown and white, borne in 

 dense racemes. G. dilatatum, R. Br., 

 of India, 6-12 in. high, fls. white 

 marked pink and yellow, borne on an 

 erect scape. G. plicatum, Voigt.= 

 Phaius. L. H. B. 



GEONOMA (Wittstein gives this 

 interesting explanation: "Greek, geo- 

 nomos, skilled in agriculture: for this 

 tree puts forth buds at the apex of 

 its stem which become new trees"). 

 Pabnaceze, tribe Arecese. Slender spine- 

 less palms with ringed, reed-like stems 

 much cultivated for their excellent decorative pos- 

 sibilities. 



Leaves terminal or alternate, usually crowded in 

 showy clusters; blade entire, 2-lobed at the apex, or 

 more or less pinnatisect; segms. acuminate, 1-nerved, 

 with the margins broadly recurved at the base; rachis 

 acute above, convex on the back; petiole nearly cylin- 

 drical, concave at the base above; sheath tubular: 

 spadices ascending or recurved, simple, forked or panic- 

 ulately branched, slender or stout, often colored; 

 spathes 2, often deciduous before flowering, or obsolete, 

 the lower one partial, truncate, concave, the upper 

 compressed or fusiform; fls. monrecious in each spadix, 

 borne in the furrows of the spadix, at length partially 

 exserted, when in 3's the upper one pistillate; cells of 

 the anthers twisted: fr. small, globose, black. Species 

 about 100. Trop. Amer. G.C. II. 24:586. A.G. 16: 

 345. For G. Ghiesbreghtiana, see Calyptrogyne. 



Several of the members of this extensive genus of 

 small-growing palms are useful for the greenhouse, 

 though most attractive while in a small state, from the 

 fact that geonomas soon begin to form a stem, and 

 when aged become rather scantily furnished specimens. 

 These palms are by no means difficult to grow, and do 



85 



1629. Geonoma Spixiana. 



not require a very high temperature, their natural 

 habitat being the mountains of Central and South 

 America, some of the species being found at an altitude 

 of over 4,000 feet above sea-level. Geonomas form part 

 of the undergrowth on their native mountains, and are 

 said never to appear in the open country unsheltered 

 by trees of larger growth; therefore, shade is necessary 

 for them when cultivated under glass. The old practice 

 of growing geonomas in a very light peaty soil does 

 not seem to be the only method, for excellent results 

 have been secured by growing them in a good loam, 

 well manured and well drained, giving an abundance of 

 water and a night temperature of 60. Red spiders 

 and thrips are the most troublesome insects to which 

 these plants are subject, and both of these pests multi- 

 ply much more rapidly if the plants are kept too warm 

 and dry. (W. H. Taplin.) 



The most useful species from a commercial point of 

 view is G. Riedeliana (G. gracilis), which reminds one 

 of Cocos Weddelliana, but has longer leaflets. The 

 species are undoubtedly con- 

 fused under cultivation, and 

 often unidentified. They are 

 said not to be grown in the 

 open in southern California, 

 at least, not to any extent. 

 The species here listed 

 appear to be those of most 

 horticultural importance 

 here. 



A. Los. simple, 2-lobed at the apex. 

 B. Cuneate-oblanceolate, rusty, tomentose. 

 Spixiina, Mart. Fig. 1629 (adapted 

 from Martius' work on palms). St. 

 slender, solitary, 6-9 ft. high: Ivs. in a 

 dense, graceful cluster; blades 3-5 ft. 

 long, bifurcate one-fourth of their 

 length, each lobe lanceolate-acuminate, 

 divergent: spadix from between the 

 Ivs., about 3 ft. long; fls. small, the calyx 

 and corolla equal. W. Brazil. 



BB. Cuneate-ovate, plicate. 

 Seemannii, Hort. Low, 1-3 ft. high: 

 Ivs. all alike, the first 2 in. long, the 

 later ones 10 in. long, entire, or 2-lobed, 

 usually deeply cleft at the apex, plaited, 

 feather-veined; stalk triangular, sheath- 

 ing at the base, with broad, scarious 

 margins: fls. unknown. F.M. 1869:428. 

 Cent. Amer. 



AA. Lvs. pinnate. 

 B. Basal If. -segms. narrow; the upper ones the broadest. 



acaulis, Mart. Acaulescent: Ivs. in a congested, 

 rosette-like cluster, long-petioled, 3-4 ft. high; blade 

 unequally pinnatisect, with usually 6 segms. on both 

 sides of the rachis; 22-25-nerved, basal segms. 4 lines 

 wide, spreading, the middle and upper erect-spreading 

 at an acute angle, %^4 in. wide, the apical very wide: 

 spadix stiff, usually about 18 in. long, the stalk very 

 thick; fls. numerous: fr. unknown. Cent. Brazil. 



BB. Broad and narrow segms. irregularly intermingled. 

 c. Blade of If. 6 ft. long; petiole 1 ft. long. 



Pohliana, Mart. St. 12-15 ft. high, slender, densely 

 ringed, columnar or reedy: Ivs. very numerous, erect or 

 spreading, forming a much congested, showy cluster, in 

 adult specimens; segms. very unequal, linear-lanceo- 

 late, falcate-acuminate, few-nerved and many-nerved 

 intermixed, 16-20 in. long; petioles very short: spadix 

 scarcely showing among the dense cluster of Ivs. Trop. 

 Brazil. Cult, most advantageously in a warm moist 

 house. The young specimens are attractive for potted 

 plants. 



