PEDILAXTHUS 



PELARGONIUM 



2525 



purple, M~M m - long. m dense terminal cymes, glabrous 

 inside and out; pedicels of the stamens hairv, of the 

 ovary smooth. Fla. to Venezuela. B.R. 837^ L.B.C. 

 8:727. B.M. 2514. Two varieties are in cult., cuad- 

 latus and variegatus, Hort ., both with white-bordered Ivs. 

 padifolius, Poit. Sts. green, glabrous: Ivs. few, 

 oblong-ovate, obtuse: cymes terminal, open; tube of the 

 involucre hairy only within; pedicels of both stamens 

 and ovary hairy. \V. Indies. 



AA. Lobe above the spur 2-parted; bracts of the infl. green 



aphyllus, Boiss. Branches slender, leafless: cymes 

 terminal; the pubescent peduncle attached at the back 

 of the involucre, which is hairy within; pedicels of the 

 stamens and ovary glabrous. Mex. Intro, as a wax- 

 yielding plant. 



macrocarpus, Benth. Shrubby: sts. whitish: Ivs. 

 minute: cymes open, few-fld.; peduncle attached to the 

 center of the involucre, pedicels glabrous. W. Mex. 



J. B. S. NORTON. 



PEDIOCACTUS (plains cactus). Cactdceae. Globular, 

 resembling in habit and flower the so-called mammil- 

 larias: fls. small, with a rather indefinite funnel-shaped 

 tube; petals pinkish, broad; sepals smaller than the 

 petals and duller in color; bracts on corolla-tube few; 

 stamens numerous; ovary green, nearly globular, usually 

 without bracts (rarely 1, otherwise naked), 

 apex with a truncate or depressed scar left by 

 the deciduous corolla: fr. dry, greenish, bursting 

 irregularly; seeds dull black, tuberculate, keeled 

 on the back, with a large sub-basal hilum. The 

 fl. originates just above the spine areole on 

 the very young tubercles, and therefore this 

 genus belongs to the Echinocactus type rather 

 than to the so-called mammillarias. The seeds are also 

 of the Echinocactus type. 



Simpsonii, Brit. & Rose. Subglobose or depressed, 

 turbinate at base, simple, often clustered, 3 }-5 in. 

 diam.: ribs 8-13, only indicated by the spiral arrange- 

 ment of the prominent tubercles, which are Y^'^m 

 long, somewhat quadrangular at base and cylindric 

 above; exterior spines 20-30, slender, rigid, straight, 

 whitish, yy-ytf&.. long, with 25 additional short seta- 

 ceous ones above; interior spines 8-10, stouter, yellow- 

 ish and reddish brown or black above, erect-spreading, 

 -,in. long; no truly central spine: fls. M-^sin. long 

 and nearly as broad, yellowish green to pale purple. 

 Mountains of Colo., Wyo.. Utah, and Nev. This spe- 

 cies does not grow well in cult., although it is fre- 

 quently intro. This is the species which forms the 

 "snake cactus" or "brain cactus" often seen in cult. 



J. N. ROSE. 



PELARGONIUM (storfc, because the fruit is long and 

 slender like a stork's bill). Geraniacex. GERANIUM of 

 gardens. PELARGONIUM. STORK'S BILL. Many kinds 

 of pot-plants, popular for indoors and for bedding; and 

 some of them much planted permanently out-of-doors 

 in California and elsewhere; flowers showy. 



Plants of various habit : some are fleshy and tuberous 

 and are treated as succulents, but those commonly 

 grown are erect or trailing leafy herbs or woody below 

 (sometimes shrubby) with sts. somewhat soft and suc- 

 culent or small and firm: Ivs. mostly opposite, entire 

 to decompound, stipulate, the foliage often strong- 

 scented: infl. mostly umbel-like, on axillary peduncles; 

 fls. irregular, the petals 5 (rarely fewer by abortion), 

 the 2 upper usually larger and more prominently 

 colored, the lower mostly narrow and rarely very small, 

 the colors pink, red, purple, white, sometimes yellow, 

 often attractively blotched or veined; calyx 5-parted (or 

 the sepals said to be connate at base), the uppermost 

 segm. produced at base into a slender nectar-bearing 

 tube or spur adnate to the pedicel; stamens 10, of 

 which 7 or less are anther-bearing and fertile: fr. of 5 

 valves, each 1-seeded and separating from the beak- 



like apex mostly by coiling and more or less hygro- 

 metrically. Nearly all the pelargoniums are from S. 

 Afr. All the species mentioned in this article are from 

 that region, unless otherwise stated. Harvey, in Vol. I 

 of Harvey & Sender's Flora Capensis (1859^60), admits 



2836. Pelargonium inquinans (and a variety of it) as figured 

 by Dillenius in 1732. 



163 species; and his descriptions are followed closely in 

 the characterizations of species given below. Knuth, 

 the most recent monographer (in Engler's Pflanzen- 

 reich, IV. 129, 1912), admits 232 species and very many 

 well-marked hybrids. Pelargonium is distinguished 

 from the genus Geranium by technical characters. In 

 most cases, the fls. of Geranium are regular, but those 

 of Pelargonium are irregular, the 2 upper petals differing 

 from the others in size and shape and often hi coloring. 

 The most constant difference between the two genera 

 is the presence hi Pelargonium of a nectar-tube, extend- 

 ing from the base of one of the sepals and adherent to 

 the side of the calyx-tube or pedicel. This tube is not 

 seen by the casual observer, but it may be discovered 

 by making a longitudinal section of the fl. and pedicel. 

 The person who wishes to study the contemporaneous 

 evolution of plants may find his heart's desire in 

 Pelargonium. With great numbers of species and many 



