PISTIA 



shaded during the middle o£ the day in summer, or the 

 foliage is likely to become yellow and sickly-looking. 

 In winter the plants are liable to some decay. 



Botanically, the genus Pistia is unique. The latest 

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

 Phaner. 2, 1879) makes Pistia the sole representative of a 

 subfamily, one of his 10 primary natural divisions of the 

 Arum family. He regards the Pistias as all one species, 

 though 9 or more have been described. He recognizes 

 4 well-marked varieties, based iipon the shape of the 

 Ivs., which he ca!I« rjnwrrfn, .tpafhithtta, obcordata and 

 Unguiformis. Afrir the f.intincntal fashion Engler 



takes no m f tli.v,- 'i^ ;i typ.- tn which the others are 



referred. It i^ laMl.aM,- tli;it tli.' form with obcordate 

 Ivs. is the <<nv .-liii-lly '/ult, in .Vnn-rican water gardens. 

 Generic characters: fls. unisexual; spadix without ap- 

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

 whorls, with 2 very short stamens which are much 

 grown together and inserted at the apex of the spadix; 

 female lis. solitary: ovary 1-celled; ovules numerous, 

 orthotropous, in 4-6 series ; fr. baccate, irregularly 

 breaking open, normally with many seeds. 



Stratidtes, Linn. Water Lettoce. Tropical DtrcK- 

 WEED. Tender perennial aquatic herb 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. 6:625. W. M. 



PlSUM (Greek and Latin name of pea). Legtimi- 

 ndsie. About 6 species of mostly climbing herbs of the 

 Mediterranean region and eastward, one of which, P. 

 sativtim, is the common Pea. Calj-x-tube oblique at the 

 base, the lobes more or less leafy; standard obovate or 

 orbicular ; wings adhering to the keel ; style mostly 

 rigid, widened above, bearded down the inner margin: 

 Ifts. 1-3 pairs, the leaf ending in a tendril or point, the 

 stipules conspicuous. Annual or perennial, of easy cul- 

 ture. Hardy. 



PITCHER PLANTS 



1359 



ixy^). 



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

 glabrous and glaucous, tendril-climbing: stipules large 

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

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

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

 See Pea. 



Var. arvfinse, Poir. (P. arv(nse, Linn.). Field Pea. 

 Fls. usually bluish or dull white, with purple wings; 

 seeds angular, often gray. Grown for forage. 



fonndsum, Stev. (Orobus formfisws, Stev. Ldthyms 

 frigichis, Schott & Ky. Plswm Aticheri, Janh. & Sp.). 

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

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

 cronate: peduncles 1-fld., the fls. purplish: legume 



86 



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

 The Orobus formosHS 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 H. B. 



PITANGA. Eugenia Micheli. 



FITCAIBNIA (W. Pitcaim, a London physician). 

 Sromelidc€(e. 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 &s. are perfect; sepals 3, free; petals 3, 

 unguiculate, erect or spreading at the apex, usually with 

 2 small scales at the base; stamens 6, free, with linear 

 anthers: fr. a 3-valved capsule, with numerous seeds. 

 See also Baker in Journ. Bot. 1881. For pictures of two 

 Mexican species, P. Jaliscana and P. Palmeri, see G.F. 

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

 name. For other species, see Puxja. 



For culture of Pitcairnias, follow advice given under 

 Billbergia. 



coralllna, Lind. & Andr^. Stemless: 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-thirtl 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.Klotzscliictna, 'Baker) . Stemless: 

 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. 



caertlea, Benth. & Hook. (Piiija cmrfdea, 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. 



alpfistris {P. cwrulea. Baker. Pfnja Wh^tei, Hook. f. 

 Puya atp4siris, Poepp.). Flower-cluster much branched 

 or panicled, with bracts more serrate than in P. carulea: 

 fls. very large and showy, with a flaring mouth, dull 

 metallic blue. Chile. B.M. 5732. -A plant in bloom has 

 the habit of a yucca. This and P. caruleav)i\\ probably 

 stand considerable frost. 



heteroph^lla. Beer (P. Morrhtii, Lam. Pttija hetero- 

 phi/lla, 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. 



PITCHEE PLANTS are carnivorous plants bearing 

 pitchers which in some cases contain a liquid secreted 

 by the plant by the aid of which the plant digests the 

 bodies of insects. The native Pitcher Plants of our 

 northern and southern states are Sarracenias. The Cali- 

 fornia Pitcher Plant is described under Darlingtonia. 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- 

 tion from widely different parts of the vegetable kingdom. 

 The genus Nepenthes might possibly be derived from the 

 Aristolochia family, being a degenerate along one line, 



