1338 



PILOCEREUS 



7. Houll6tii, Lem. Tree-like, attaining 40 ft. in height: 

 branches divaricate; cultivated plants usually 3-4 in. in 

 diam: ribs 6-8, rounded, glaucous ; radial spines 7-9, 

 spreading Vi in. long, honey yellow, central twice as 

 long and stronger: areolae of the sterile stem with more 

 or less hairs, which in the fruiting area are very numer- 

 ous, making a shaggy tract sometimes 1 ft. long: fls. 3 

 in. long, imbedded in the wool, turbinate, greenish red 

 outside, rose-red within: fr. dark red, depressed-globose. 

 Mexico. R.H. 1862, pp. 427-430. 



AAA. Fruiting area a prominent cephalium composed of 

 dense locks of u'oolly hairs intermixed with 

 bristles, unilateral except sometimes in P. 

 chrysomallus. 

 B. Lo)ig hairs absent except in the cephalium. 



8. Columna-Trajani, Salm-Dyck. Tree-like, attaining 

 a height of 50 ft. and a diam. of over 2 ft., simple below: 



areolsB large, elliptic ; radial 

 ' ./ spines 10-12, the upper very 



short, the lower longest, nearly 

 an inch long ; centrals 2, the 

 upper an inch long, the lower 

 4-5 in. : fls. about 2 in. long, 

 scarcely projecting from the 

 unilateral woolly and bristly 

 £?- -_ cephalium. Mex' R.H. 1890, p. 

 129. The specific name refers to 

 the famous Trajan's Column. 



BB. Long hairs covering all but 

 the oldest ports of the 

 plant. 



9. chrysomallus, Lem. Tree- 

 like, with erect In-anches, reach- 

 ing a height of 30 ft. : ribs in 

 cultivated plants 13 : areolae 

 with long hairs ; radial spines 

 11-13, the upper /i in. long, the 

 lower twice as long; centrals 4, 

 still longer; all the spines am- 

 ber-yellow, becoming brown: 

 cephalium terminal or some- 

 times unilateral, a foot long, 

 woolly and setose. Mex. 



10. senilis, Pfeiff. Old Man 

 Cactus. Columnar, reaching a 

 height of 35 ft. and a diam. of 

 1 ft., branching at the very 

 base, the branches becoming 

 parallel with the parent: ribs 

 20-30, very little elevated ; areolae 

 bearing 20 to 30 white, wavy 

 bristles 2-5 in. long; later ap- 

 pear also, at first 1, then 3-5 

 strong, yellowish spines : fls. 

 very numerous in the cephal- 

 ium, nearly 4 in. long, red out- 

 side, reddish white within: fr. 



violet, 2 in. long. Central Mex. R.H. 1889, p. .568; 1890, 

 p. 128. 



11. Daiitwiztii, Haage {P. Haclgei, Poselg. ). Colum- 

 nar, reaching 5 ft. in height, 4 in. in diam. : ribs 25-30, 

 low, ol)tuse : areolae close together, bearing over 20 

 needle-like, spreading and interlocking spines, and also 

 copious long, white, curled hairs which cover the whole 

 upper part of the plant, like a spider's web: cephalium 

 and fl. not certainly known. Northern Peru. G.C. 1873:7. 

 F.S. 21:2163. 



AAAA. Fruiting areoltp and younger parts of the plant 

 bearing short hairs, but cephalium wanting. 



12. ex^rens, Schura. {P. v\rens, Lem.). Branching at 

 base, 3-4 ft. high, 2-3 in. in diam., tapering above: 

 ribs 4-6, ol>tuse, the sterile shoots with short, sparse, 

 woolly hairs at the top; spines comiiionly 7 radials, 

 very short, 1-3 centrals 4 times as lotig; woolly hairs 

 much more abundant on the blooming plant: fls. about 

 3 in. long, trumpet-bell-shaped, without wool or spines. 



1803. Pilocereus Schottii. 



PIMELEA 

 PILTJMNA. See Trichopilia. 



PIMELEA (Greek, fat; referrmg to the fleshy seeds). 

 Thymehedcece. Rice Flower. A genus comprising- 

 many showy species, and confined almost exclusively 

 to Australia and neighboring islands. They are mostly 

 delicate shrubs, fitted only for greenhouse culture, 

 though reported to be hardy in the open wherever the 

 lemon can be successfully grown. Lvs. nearly always 

 opposite, always simple and entire: inflorescence usu- 

 ally a terminal head or cluster, never umbellate, often 

 with an involucre of 4 or more bracts at the base : per- 

 ianth tubular, with a spreading (rarely erect) 4-lobed 

 limb: stamens 2, inserted in the throat opposite the 2 

 outer perianth-lobes: ovary 1-celled: fr. a small drupe. 

 Of the many species, only three (P. decussata, P. li- 

 gustrina and P. spectabilis) have been actually intro- 

 duced into the U. S., but there are so many other very 

 showy species, some of which are already in the Old 

 World, that in all probability more will soon be found 

 in our collections for greenhouse culture. For the lat- 

 ter the soil should be a mixture of peat and loam, with 

 enough sharp sand added to make it "gritty," and spe- 

 cial care given to insure perfect di-ainage. After bloom- 

 ing, the plants should he cut back severely to stimulate 

 new growth. They can be propagated from either seed.s 

 or cuttings. Ernest Braunton writes: "P. decussata 

 is an elegant little shrub, of uncertain existence. In 

 southern Calif, it attains a height of 3 ft., with the 

 same width at the top, flowers magnificently and then 

 dies. In northern Calif, it does the same. In the open 

 ground it lives 3-5 years, and must have shade." 



Arnold V. Stubenrahch. 



Cuttings of well-ripened wood of P. spectabilis and 

 P. decussata root freely at 60° placed under a bell-glass, 

 in a shaded house. They are not sti'ong growers and 

 must not be over-potted. During the summer they do 

 best when plunged outside but covered with lath racks. 

 They may be kept with auriculas. During the winter 

 they may be kept with ericas at 40-45° at night, and they 

 will come in at Easter without forcing. They are rather 

 slow-grqwing plants for a commercial man, but they 

 probably will become profitable. P. decussata, espe- 

 cially, is one of the finest of pink greenhouse shrubs. 



H. D. Darlington. 



The following are all natives of Australia, except 

 when otherwise stated: 



arenfria, 9. 

 deciitsata, 13. 

 drupacea, 2. 

 fernighiea, 1.3. 

 glauca, 6. 

 graciliflora, 8. 



hypericina, 3. 

 imbrieata, 16. 

 ligiistrina, 4. 

 linifolia, 7. 

 longiflora, 1. 

 nivea, 12. 



rosea, 10. 

 spatliulata, 15. 

 spectabilis, 14. 

 suaveolens, .5. 

 sylvestris, 11. 



Brazil. 



Katharine Brandegee. 



PILOGYNE. See Melothria. 



A. Involucral lvs. absent 1. longiflora 



AA. Involucral lvs. reduced to 3 small 



bracts 2. drupacea 



AAA. Involucral lvs. 4-8. 



B. Lvs. distinctly penniveined. 



c. Fls. white 3. hypericina. 



4. ligustrina 

 cc. Fls. rose-colored or yellowish. 5. suaveolens 

 BB. Lvs. not penniveined or very 

 obscurely so. 

 c. Color of invohicral lvs. gi-een. 

 D. Fls. white. 



E. Perianth -tube cylindri- 

 cal 6. glauca 



7. linifolia 

 EE. Perianth -taJie wider at 



top 8. graciliflora 



EEE. Perianth-tube narrower 



at top 9. arenaria 



DD. Fls. rose-colored. 



E. Perianth-tube cylindri- 

 cal 10. rosea 



EE. Perianth-tul'i' wider at 



top n . sylvestris 



DDD. Fls. u-hife and pitik in 



same head 12. nivea 



