PISTIA 



shaded during the middle of the day in summer, or the 

 foliage is likely to become yellow and sickly-looking. 

 In winter the plants are liable to some decay. 



Botauioally, the genus Pistia is unique. The latest 

 monographer of the aroids (Engler, in DC. Monogr. 

 Phaner. 2. 1S79) makes Pistia the sole representative of a 

 subfamily, one of his 10 primary natural .livi-^ion'^ of the 



Arum family. He regards the I'i-n i- .- ill -p.cics. 



though 9 or more have been dt-^-r i ; I i - > u'liizes 

 4 well-marked varieties, based u; : i "I the 



Ivs., which he calls cuneata, sj>nlh'<'''ii'' . .'. .,;-(/.( ami 

 linguiformis. After the continental fashicm Engler 

 takes no one of these as a type to which the others are 

 referred. It is probable that the form with obcordate 

 Ivs. is the one chiefly cult, in American water gardens. 

 Generic characters: fls. unisexual; spadix without ap- 

 pendage, adnate to the back of the spathe; male fls. in 

 whorls, with 2 very short stamens which are much 

 grown together and inserted at the apex of the spadix; 

 female Hs. solitary: ovarv 1 .-..li.-l: •.v\iles numerous, 

 orthotropous, in i-G -. ■ -■ t l , .r-ite, irregularly 



breaking open, normall\ - ,1s. 



Stratidtes, Linn, ^\■\n .. Li Tropical Duck- 

 weed. Tender perennial iniuaiic hcil* described above. 

 The small white fls., though inconspicuous and borne 

 at the bottom of the cup of Ivs., are large enough to 

 show at a glance their relation to the Arum family. 

 B.M. 4564. F.S. 0:625. \y. M. 



PtSUM (Greek and Latin name of pea). Legitmi- 

 nusip. About 6 species of mostly climbing herbs of the 

 Mediterranean region and eastward, one of which, P. 

 .•(a/trMm, is the common I'l ,i i :il\\ i uImi oblique at the 

 base, the lobes more <•>■ I nnlard obovate or 



orbicular; wings adln i . , 1 ; style mostly 



rigid, widened above, l.i.ni. ,i ,; ;mi lii.' inner margin: 

 Ifts. 1-3 pairs, the leaf .-rulinK ui a i.-ndril or point, the 

 stipules conspicuous. Amuial or perennial, of easy cul- 

 ture. Hardv. 



PITCHER PLANTS 



1359 



1835. Pisum sativum (X M). 



sativum, Linn. Garden Pea. Fig. 1835. Annual, 

 glalirous and glaucous, tendril-climbing: stipules large 

 and leafy (usually as large as Ifts. I : Ifts. oval or ovate, 

 2-3 pairs, the leaf ending in tendrils: fls. few, on an 

 axillary peduncle, white : seeds globular. Eu., Asia. 

 See Pea. 



Var. arvfinse, Poir. {P. arvinse, Linn.). Field Pea. 

 Fls. tisually bluish or dull white, with purple wings: 

 seeds angular, often gray. Grown for forage. 



fonndsum, Stev. (Orobux formdsus, Stev. Ldthyrus 

 Mqidus, Schott & Ky. Plsnm Aiicheri, Jaub. & Sp.). 

 Perennial, 1-2 ft. tall, not climbing: stipules sagittate- 

 ovate: Ifts. 1 pair, small, ovate-rhomboid, entire, mu- 

 peduucles 1-fld., the fls. purplish: legume 



86 



smooth, as also the ovate seeds. Asia Minor, Persia.— 

 The Orobits forniosus that has appeared in the trade 

 seems not to be this plant, for the cult, plant is de- 

 scribed as having "dense spikes of purple flowers." It 

 is not known to the writer whether the true P. formosum 

 is in the trade. l_ jj_ b. 



PITANGA. Eugenia Mieheli. 



PITCAIRNIA (W. Pitcairn, a London physician). 

 Broiiitli<ice<r. Mez, the most recent monographer of 

 the bromeliads (DC. Monogr. Phaner. 9), admits 134 

 species of Pitcairnia. They are American, mostly tropi- 

 cal. In choice collections, various species of Pitcairnias 

 may be expected, but very few of them are in the Ameri- 

 can trade. They are billbergia-like, very short-stemmed 

 perennial herbs or subshrubs with dense rosettes of nar- 

 row, often prickly-margined leaves, and a central spike 

 or raceme of long-tubular red, yellow or nearly white 

 flowers. The fls. are )n'rtVi-t; si-pals 3, free; pitals 3, 



anthers: fr. a 3-v;;: .;::,-, i , i. ;,-. ■ ■ •\s. 



See also Baker in .liui n. l;--i . I -- 1. I i.r [uri u i , - ,.| two 

 Mexican species, P. Jahsnnia and 7'. I\umi'rt, si-e (J.F. 

 1:197 and 211. P. farinosii is an undetermined trade 

 name. For other species, see Puya. 



For culture of Pitcairnias, follow advice given under 

 Billbergia. 



COTalllna, Lind. & Andr^. Steraless: outer Ivs. hard 

 and dry, -without marginal spines, the inner ones with 

 brown-spined petioles and broad plicate recurved blades 

 which are somewhat scurfy on the back: peduncle about 

 1 ft. long, bright red, the raceme of about equal length 

 and drooping: fls. coral-red, about 3 in. long, the calyx 

 part comprising about one-third of this length; stamens 

 as long as the petals, with white filaments; stigmas 

 twisted. Colombia. R.H. 1875: 250. B.M. 6600. -Per- 

 haps the best species. 



Moritziina.Koch (P.KMzsclnclna,BD.'keT) . Steraless: 

 Ivs. linear, in a rosette, 12-18 in. long, usually spineless 

 and the petiole short or none: raceme 1 ft. or less long, 

 on a leafy peduncle of about the same length : fls. red 

 or yellowish, usually not 3 in. long. Guatemala. 



cserCilea, Benth. & Hook. (Puya carulea, Lindl.), 

 Foliage pineapple-like, with linear very acute Ivs. 2 ft. 

 long, which are spinose-dentate and nearly glabrous: 

 peduncle 3-4 ft. tall, the bracts membranaceous, the in- 

 florescence somewhat branched but not loose: fls. narrow- 

 tubular, the petals blue and oblong-obtuse, the sepals 

 much shorter and green and obtuse; alternate stamens 

 shorter. Chile. B.R. 26:11. 



alp6stris [P. cwridea. Baker. Puya TV7ii)tei, Hook. f. 

 Ptiya alpisMs, Poepp.). Plower-clustfr miicli branclu-d 

 or panicled, with bracts more serrate than in /', r.rnilru: 

 fls. very large and showy, with a Ha'inu- nHniili. dull 

 metallic blue. Chile. B.M. 5732.-A i.l.nt in l.ln.nn has 

 the habit of a yucca. This and P. <■; ,f'/i(i h ill pmhahly 

 stand considerable frost. 



heteroph^Ila, Beer (P. Morrlnii, Lam. Puya lietero- 

 phylla, Lindl.). Stemless: Ivs. of two kinds, the outer 

 ones narrow and spiny, brown, and being the termina- 

 tion of bulb-like scales, the later ones being longer 

 (16-24 in.) and green and entire: fls. flesh color or light 

 red, in a close oblong spike that is shorter than the 

 green Ivs., the latter arising, however, from separate 

 shoots. Mex. to Venezuela and Ecuador. B.R. 26:71. 

 -Odd. L. H. B. 



PITCHEB PLANTS are <-arniv.,r..iis plants bearing 

 pitchers which in some <'a-i , -ni lin i 11 , liM , r. ted 

 by the plant bv the aid et ' ' , ' ■ ' • the 



bodies of insects. The ,,., I I i our 



northern and southern sta I, .h -,;;,., i.,.i I i., Cali- 

 fornia Pitcher Plant is de.scnh. ,1 uiuK !■ iJailiii-l'.iua. The 

 favorite Pitcher Plants of greenhouses are Nepenthes. 

 All these plants have a morphological resemblance in 

 their pitcher -bearing foliage, but their flowers and 

 seeds are so apparently unlike that they suggest deriva- 

 tiiin frciTn widely ilitTerent T>arts of the vegetable kingdom. 

 The geiiu^ Ne|peiiihes In i 1,'ht posslbly bc dcrl vcd f rom tho 

 Aristc.lcieliia family, being a degenerate along one line. 



