1184 



OXYDENDRUM 



OYSTER PLANT 



late, 3-6 in. long, glabrous, veiny, slender-stalked: 

 clusters borne on leafy shoots of the season: fls. open- 

 ing slowly. Rich woods, Pa. and Ohio, along the Al- 

 leghenies to Fla. B.M. 905. B.B. 2:571. S.S. 5:235. 

 F. W. BARCLAY and W. M. 



1604, Sour-wood or Sorrel-tree, Oxydendron arboreum 



OXYLOBIUM ( Greek, sharp pod). Leguminbsw. This 

 is one of many genera of Australian shrubs with pea- 

 like fls. which are little known in cultivation. For 

 winter bloom under glass none of them equals Cytlsus 

 Canariensis . Oxylobium is a genus of 28 species, of 

 which perhaps a dozen have been cult, in Europe. Their 

 fls. are yellow, or more or less flushed with red on the 

 keel or the base of the standard. O. Callistachys is per- 

 haps the best for conservatories. In America it is cult. 

 only in S. Calif. 



Generic characters: Ivs. very short-stalked, opposite 

 or more or less whorled, rarely scattered or alternate: 

 fls. in terminal or axillary racemes; petals clawed; sta- 

 mens free : ovary villous, sessile or stalked, 4-30-ovuled. 

 Nearest to Chorizema, but the keel is about as long as 

 the wings, while in Chorizema the keel is much shorter. 

 The following species was considered the type of another 

 genus ; it is distinguished from all other species of Oxy- 

 lobium by the incomplete dehiscence of the pod. See 

 Flora Australiensis 2:14 (1864). 



Callistachys, Benth. Tall shrub: Ivs. mostly in ir- 

 regular whorls of 3, varying from ovate-oblong and 

 l%-2 in. long to lanceolate and 4-5 in. long, leathery, 

 silky-pubescent beneath when young: racemes oblong 

 or pyramidal, 2-6 in. long. B.R. 3:216 (as Callistachys 

 lanceolata). B.M. 1925 (as C. ovata). P.M. 8:31 (as C. 

 longifolia). L.B.C. 20:1983 (as C. retusa). J.H. III. 

 35:35. 



OXYPfiTALUM (Greek, sharp petal). Asclepiadacece. 

 O. cceruleum is a tender twining herb from the Argen- 

 tine Republic with changeable 5-lobed fls. about an inch 



across. The fls. are said to be pale blue when they first 

 open, then purplish, and when withered lilac. Not cult, 

 in America, but apparently desirable for cultivation here. 

 The following are perhaps obtainable from Europe: O. 

 appendiculatum, with pale yellow, fragrant fls.; O. 

 Banksia, with purple fls., and O. solanoides, blue, 

 tinged rose. 



Oxypetalum is a genus of about 50 species, mostly 

 South American and largely Brazilian herbs or sub- 

 shrubs, twining or not : Ivs. opposite: calyx 5-parted: 

 corolla deeply 5-cut, short-tubed: scales of the corona 5, 

 fastened at the base of the corolla and staminal tube. 



caeruleum, Dene. Downy: Ivs. short-petioled, oblong, 

 one of each pair of the upper Ivs., 3-4-fld. : corolla-lobes 

 but cordate-hastate at the base : peduncles axillary from 

 spreading : scales of the corona 5, erect, darker blue, 

 fleshy, exserted, recurved and notched at the apex. 

 B.M. 3630 (Tweedia versicolor) . 



OXYTROPIS (Greek, sharp keel). Leguminosce. 

 Three Colorado wild flowers are offered under this 

 name. The fls. are pea-shaped, borne in spikes, and 

 range from white through blue and purple to crimson. 

 The plants are tufted, and the Ivs. are odd-pinnate, 

 have 7-16 pairs of Ifts., and are often woolly white 

 beneath. O. Lamberti is one of many plants that have 

 been charged with being the "Loco weed'' which ruins 

 western horses. This genus, according to E. L. Greene 

 (Pittonia 3:208), should be referred to Aragallus. 

 Aragallus is reviewed in Erythea 7:57-64 (1899), but 

 the genus is not defined. It is closely related to Astrag- 

 alus, and differs essentially in the pods being usually 

 2-celled instead of 1-celled. About a dozen kinds of 

 Old World Oxytropis said to be cult, in Europe, mostly 

 in rockeries. They are hardy, easily prop, by seed or 

 by division, and prefer a dry, sandy loam. These 

 plants are of very minor value horticulturally. 



A. Stipules free: pod 1-loculed. 



deflexa, DC. (Aragallus defUxus, Heller). A foot or 

 less high: Ifts. crowded in 12-16 pairs, lanceolate to 

 oblong, 3-6 lines long : fls. about 3 lines long : pod 

 1-celled. Mts., Brit. Amer. to Colo, and Utah. Very 

 distinct species, by reason of its stipules. 



AA. Stipules adnate to the petiole: pod S-loculed. 



Lambertii, Pursh (Aragallus Ldmberti, Greene). 

 Lfts. about 7 pairs, 4-16 lines long: spike sometimes 

 short-oblong, densely fld., often long and sparsely fld.: 

 fls. 1 in. across, typically purple or violet; calyx not 

 inflated, distinctly surpassed by the mature pod : pod 

 turgid but not membranous-inflated, more or less 

 leathery, subterete, neither glandular nor viscid, im- 

 perfectly 2-loculed or less. Common on the prairies. 

 B.M. 2147 (dark blue). B.R. 13:1054 (blue). V. 3:138. 

 Aven Nelson, in Erythea 7 :62, says that the species should 

 be restricted to the purple- and violet-fld. forms. D. M. 

 Andrews offers a crimson-fld. form, and also var. spi- 

 cata, which has large spikes of white fls. \\r f ]\f 



OXYtRA. Sec L>j!. 



OYSTER PLANT or SALSIFY. 



folius. 



Tragopogon porri- 



