PILEA 



PILOCEREUS 



1337 



flowers are monoecious or dioecious, mostly very small 

 and in axillary clusters; stamens 3-4, and the sepal- 

 lobes in the staminate fls. of the same number; sepal- 

 lobes of pistillate fls. 3, the ovary 3-angled and erect 

 and bearing a sessile tufted stigma, with 3 scale-like 

 staminodiums: fr. an akene, ovate or nearly orbicular, 

 compressed, more or less invested in the perianth. 

 There are 150 or more species of Pilea, one of which, 

 P. pumila, is a small nettle-like plant growing in the 

 northern states. 



The Artillery Plants of the gardens are small branchy 

 half-succulent herbs, usually grown in pots and allowed 

 to reach a foot or so in height. The gracefully curving 

 fronds of small ovate or obovate shining leaves are 

 much prized. They are easy to grow, being propagated 

 by cuttings. They thrive best when given an abun- 

 dance of water. Sometimes they are used as edgings in 

 orchid houses, to screen the pots with green, and they 

 also tend to equalize the moisture conditions and thereby 

 contribute to the welfare of the orchids. 



When the staminate flowers open, the pollen is usually 

 discharged forcibly and visibly. If a plant is put in a 

 sunny place when the pollen is ripe, it may set up 

 a vigorous bombardment, particularly if the foliage is 

 sprayed. (See I. H. 1, p. 64 (1854) for an account of this 

 phenomenon.) The Artillery Plant is seen in nearly 

 every greenhouse, but whether there is more than one 

 species in common cultivation it is difficult to deter- 

 mine, for specific characters are difficult to draw. The 

 Ivs., although opposite, are unequal. Usually the 

 branchlets develop alternately on the branch. 



microph^Ua, Liebm. (P. mnscosa, Lindl. P. calli- 

 trichioldes of some -d-vLthors). Monoecious: small, rather 

 weak plant: Ivs. less than % in. long as a rule, some- 

 times very small: fl. -clusters mostly sessile or nearly so. 

 S. Amer. 



serpyllifdlia, Wedd. {P. muscdsa, Hort. in part. P. 

 callitrichio'ides of some). Fig. 1802. Dioecious: plant 

 usually stronger and more upright: Ivs. usually more 

 than M in. long, and fl. -clusters more peduncled. Mex. 

 Seems to be the commoner species, but it is difficult to 

 determine them. L, H, B 



1802. Artillery Plant— Pilea serpyllifolia. 

 Separate spray natiu'al size. 



PILOCARPUS (Greek, pilos, a cap, and Tcarpos, a 

 fruit, from the shape of the fruit) . Butdcea'. Shrubs or 

 small trees, sometimes attaining 10 ft., with pinnately 

 compound Ivs. of 1-4 pairs and a terminal leaflet; the 

 Ifts. opposite, but the Ivs. usually alternate: fls. in 

 elongated racemes; petals 4-5, valvate; stamens 4-5: 

 ovary 4-5-lobed, not tubercled. The plants of the genus 

 form the source of the alkaloid "pilocarpine," and to- 

 gether with plants of several other genera, the basis of 

 the drug "Jaborandi." Seventeen species, natives of 

 tropical America, principally Brazil. 



pennatifdlius, Lem. Branchlets glabrous or puberu- 

 lent: Ivs. alternate, 1-13^ ft. long; Ifts. 2 or 3 pairs, be- 

 sides the terminal one, 3-9 in. long, oblong ; apex 

 rounded or emarginate, coriaceous, yellowish green: 

 raceme spike-like, many-fld. (about 100); rachis stout, 

 pedicels stoiit, horizontal, with 2 small greenish tooth- 



shaped bracts at their bases: fls. reddish brown, rotate. 

 Brazil. B.M. 7235. — Int. into Calif, by Dr. Franceschi, 

 and said to be hardy in the open wherever the lemon 

 can be successfully grown. 



P. Jaborandi. Holmes, has been described as P.perinatifolius, 

 by Beiith. «V Trim., but is <listiiiKuishf(l fi-om it by shorter Ivs. 

 and Ifts., stittly puliesceiit br;niclilits ;uk1 stems, more openly 

 fld. racemes, with slender rachis and pedicels, and the presence 

 of 2 inconspicuous bracteoles above the middle of the flower 

 pedicels. B.M. 7483. ARNOLD V. Stubenrauch. 



PILOCfiREUS (Latin, ;?i7?<s, hair). Cact&cece. Asome- 

 what hetereogeneous assemblage of forms differing from 

 related species principally by the presence in the fruit- 

 ing area of different or more copious and lengthened 

 hairs or bristles, in some of the species aggregated in a 

 circumscribed area and termed a cephalium. For cul- 

 ture, see Cactus. 



INDEX. 



Biiinnowii, 5. floccusus, 6. Royeni, 6. 



Celsianus, 5. fossulatus, 5. Sargentianus, 1. 



chrysomallus, 9. Haagei,\\. Schottii, 1. 



Coliimna-Triijani,8. Hoppenstedtii, 4. seoparius, 2. 



Dautwjtzii, 11. Houlletii, 7. senilis, 10. 



exerens, 12. polylophus, 3. virens, 12. 



A. Fruiting area circumferential, of lengthened bristles 

 or weak spines, without ivoolly hairs: no hairs on 

 areolw of young shoots. 



1. Schdttii, Lem. {P. Sargentidnus, Ore). Fig. 1803. 

 Branching from the base, 10-15 ft. high, glaucous: ribs 

 4-10, commonly 5; spines 4-7, very short, thickened at 

 base: areolae of the fruiting area bearing very copious 

 and long (1-3 in.) stiffish twisted bristles: fls. small, 

 pinkish, about 1 in. long: fr. soft, edible, the size and 

 somewhat the color of an olive. North Mexico and Baja, 

 California. G.F. 4:437. 



2. scop&rius, Poselg. Tree-like, richly branched, 25 ft. 

 high, 1 ft. in diam. : radial spines 12-15, very short, cen- 

 trals 7-8, not much longer; in the flowering bi-anches 

 the spines change to longer stout bristles and the areolaa 

 are closer together, forming a bristly cephalium: fls. 

 small, bell-shaped, reddish: fr. size of a hazelnut. Near 

 Vera Cruz, Mex. 



3. polyldphus, Salm-Dyck {Cereus Nickelsii, Hort.). 

 Columnar, attaining a height of 50 ft. and a diam. of 1>^ 

 ft., rarely branching: ribs 10-22, sharp-angled, shallow, 

 the old stems perfectly cylindrical: spines small and 

 bristle-like, less than }4. in. long; radials 5-6; central 

 usually 1 ; spines of the flowering area 2-3 in. long, 

 crowded: fls. large, trumpet-shaped, dark red: fr. red, 

 scaly. Mex. 



AA. Fruiting area lateral, of dense tufts of wool in 

 which the flowers are imbedded : young shoots 

 laniig inous , except in P. Hoppenstedtii. 



4. Hoppenstedtii, Web. Columnar, simple, slender, 

 reaching a height of 30 ft.: ribs numerous, more than 

 16: radial spines 14-18, very short; centrals 5-8, the 

 lower longest one reaching 3 in. ; all the spines at first 

 yellowish, then white: cephalium of 1-2 in. long tufts of 

 yellowish hairs, forming a narrow bract on the north 

 side of the plant : fls. 3 in. long, bell-shaped, whitish, 

 with rosy tips. Mex. 



5. CelsiS,nus, Lem. {P. fossulcttus, Lab.). Columnar, 

 in the gardens simple, hardly more than 4 ft. high, 3 in. 

 in diam.: ribs 10-17, bright green; areolae bearing long 

 (2 in.) white hair ; radial spines usually 9, the lower 

 one, the longest, less than 1 in. long; central usually 1, 

 sometimes 4, the longest sometimes 3 in. long, all yellow: 

 fls. not known. Andes of Bolivia. 



Var. Bninnowii, Schura. (P. Brunnowii, Haage Jun.). 

 Stem stouter: wool brownish, more copious ; spines 

 stronger and darker. 



6. Royeni, Rlirapl. (P. floccdsus, Lem.). Columnar, 

 branching, reaching 15 ft. in height, 2-3 in. in diam.: 

 ribs 9-10, obtuse bluish pruinose: spines 12-16, rigid, 

 divaricate, bright amber-yellow, the inner ones larger, 

 nearly an inch long: on the sterile branches long hairs 

 are found on areolae, on the fertile bract these are more 

 numerous and aggregated : fls. and fr. as in the last 

 species, but lighter in color. Island of St. Croix. 



