PACHYCEREUS 



2425 



Columna-Trajani, Brit. & Rose (PUocereus Coltimna- 

 Trajdni, Salm-Dyck). TRAJAN'S COLUMN. Treelike, 

 attaining a height of 50 ft. and a diam. of over 2 ft., 

 simple below: areoles large, elliptic; radial spines 1(M2, 

 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. 



marginatus, Brit. & Rose (Cereus marginatus, DC. 

 C. gemmatus, Zucc.)- Simple or branching at apex, 2-3 

 in. diam.. with 5-6 obtuse ribs, which are woolly their 

 whole length: spines short-conical, rigid, 7-9, all nearly 

 alike: fls. brownish purple, about i%in. long: fr. globu- 

 lar and spiny. Mex. Frequently used for hedges in 

 S. Mex. The st. is often covered with a woody crust. 



pecten-aboriginum, Brit. & Rose (Cbreus pecten- 

 aboriginum. Engelm.). This species is sometimes cult, 

 but does not do well under glass. The large burry frs. 

 used by the Sonoran Indians for hair-brushes are some- 

 times seen in museums and curio stores. 



Pringlei, Brit. & [Rose (Cereus Pringlei, Wats.). 

 Fig. 2695. One of the cordon cereuses of X. Mex. Not 

 so tall as Carnegia gigantea, ribs, fewer, and fls. scattered. 

 Not in cult. G.F. 2:65 (adapted in Fig. 2695). 



J. N. ROSE. 



PACHYPHtTUM (Greek, thick plant). Crassu- 

 lacese. Succulents, likely to be found in the under-glass 

 collections of amateurs, and out-of-doors far South. 

 See page 870, Volume II. 



Caulescent, more or less branched, with very thick 

 Ivs. which are often terete: fls. solitary or in secund 

 racemes; calyx deeply lobed, the lobes shorter than 

 the corolla, and appressed to it; corolla 5-7-parted 

 and not at all 5-angled; petals erect below, spreading 

 above; stamens 10, the 5 alternating with the petals 

 free from the corolla, the other 5 borne on the petals 

 each usually with a pair of appendages at the base; 

 scales broad : carpels 5, erect, free to the base. About 

 7 species from Mex. Pachyphytum is usually included 

 in Cotyledon but some recent American botanists keep 

 the genus distinct. P. uniflorum, Rose, is a stout spe- 

 cies usually woody below with green hardly glaucous 

 terete Ivs., appendaged stamens and acute calyx- 

 lobes, said to be cult, in shady courtyards at San Luis 

 Potosi, Mex. P. bracteosum, Klotzsch (Echeveria brac- 

 teosa, Lindl. & Paxt.). This species has oblanceolate to 

 spatulate thickish Ivs. and a curved, finally erect, 

 secund raceme which is 12-18-fld.: its calyx is deeply 

 campanulate with unequal lobes and a bright red 

 corolla. Mex. B.M. 4951. 



PACHYPODIUM (Greek, thick foot, alluding to the 

 roots). Apocyndcete. About 15 remarkable succulent 

 shrubs and trees of Madagascar, S. Afr. and Trop. 

 Afr., a very few of which are mentioned in horticultural 

 literature. They are grown with succulents, and prop, 

 by cuttings. Frequently the trunk is much swollen: 

 Ivs. simple, in spirals; stipules represented by rigid 

 spines; or, according to Stapf, the Ivs. suppressed with 

 the exception of a terminal rosette, and the spinous 

 stipules crowded more or less irregularly on the swollen 

 branches: cymes terminal, with few or many sessile or 

 peduncled pink, white or yellow fls.; sepals 5; corolla 

 salver-shaped, constricted at base, or funnelform to 

 campanulate, 5-lobed; anthers conniving into a cone, 

 with appendages longer or shorter than the pollen- 

 bearing part, the structure complex. P. Geayi, Cost. 

 A: Bois. Tree, 30 ft. or more, with succulent cactus- 

 like spiny trunk, branching at summit : Ivs. in terminal 

 tufts, long and narrow. Madagascar. R.H. 1907, p. 

 490. P. namaquanum, Welw. St. 5-6 ft. high and 

 9-15 in. diam., fleshy, tapering upward, tubercled and 

 spiny: Ivs. obovate-oblong to oblong, crowded in a little 



2696. Pachyrhizus 

 palmatilobus. 



crown at the top of the trunk: fls. reddish tinged 

 yellow and green. S. Afr. G.C. III. 46:371, showing 

 the strange plants in the wild. P. succulentum, DC. 

 Tuberous at base, 1-2 ft. high, producing several some- 

 what branched sts., bearing Ivs. scattered on long 

 shoots: Ivs. oblong-linear or linear, 1% in. long, pubes- 

 cent above; stipules spiny: fls. 1 in. or more across, the 

 oblong lobes white and purple. S. Afr. L. H. B. 



PACHYRHIZUS (Greek, thick, and root). Legu- 

 minosae. Climbing herbs bearing large tuberous roots 

 often 6 to 8 feet long and weighing fifty to seventy 

 pounds, which are 

 used for food and 

 as a source of 

 starch. 



Leaves pin- 

 nately 3-foliolate; 

 Ifts. stipellate, 

 lobed, 3-4 in. 

 wide: racemes 

 with swollen 

 nodes and fasci- 

 cled pedicels, 

 bracts and bract- 

 lets setaceous, 

 caducous; calyx 2- 

 lipped, limb as 

 long as the tube, 

 upper lip emargi- 

 nate, lower lip 

 deeply 3-lobed; 

 corolla much ex- 

 serted, petals sub- 

 equal, keel obtuse; 

 stamens diadel- 

 phous ;anthers uni- 

 form; ovary sub- 

 sessile, many- 

 ovuled; style long, circinate at the apex, bearded down 

 the inner side below the very oblique stigma: pod large 

 linear, turgid, deeply depressed between the seeds. 

 A genus of 3 or 4 species distributed throughout the 

 tropics of both hemispheres. Blanco, Flora de Filipinas, 

 describes and figures the roots as turnip-shaped. When 

 young, the roots are palatable. 



A. Lfts. entire. 



erosus, Urban (Dolichos erosus, Linn. D. bulbbsus, 

 Linn. P. bulbosus, Kurz. P. angulatus, Rich. Cacdra 

 erosa, Kuntze). YAM BEAN. Root tuberous: st. twin- 

 ing, shrubby, hirsute, becoming glabrate with age: Ivs. 

 pinnately 3-foliate, often long-petioled ; stipules del- 

 toid or ovate-lanceolate, short; terminal 1ft. long- 

 pedicelled, broadly cuneate at base, deeply or shallowly 

 lobed in the upper half; lateral Ifts. oblique, short- 

 pedicelled, stipels subulate : racemes 6-12 in. long, long- 

 peduncled, base often branching, branches ascend- 

 ing; calyx J^in., as long as the pedicel; corolla reddish, 

 1 in. or more long: pod 6-9 in. long, ^-^jin. broad, 

 8-12-seeded, straight glabrescent. Tropics of both 

 hemispheres. H.I. 19:1842. Eaten both raw and 

 boiled. 



tuber6sus, Spreng. JICAMA. Root tuberous, much 

 larger than the above: st. twining, 10-20 ft. long: Ivs. 

 entire or obscurely sinuate: racemes densely fld.: pod 

 8-12 in. long, %-%in. broad. Trop. Amer. H.I. 

 19:1843. Young pods superior to many cult, beans 

 in the absence of fibrous strings about the sutures of 

 the pods; seeds said to be poisonous. Perhaps only a 

 cult, form of the above species. The root is said to be 

 a great favorite with travelers, as it quenches thirst 

 and is nutritious. They are cut in thin slices and 

 sprinkled with sugar. Two forms are recognized in 

 Mex., one called agua, with a watery juice, and one 

 called leche, with a milky juice. It is said that they 



