WOOTON AND STANDLEY FLOEA OF NEW MEXICO. 507 



Hoods of the crown not corniculate, or very 

 obscurely so. 



Leaves mostly scattered, not densely 

 tomentose beneath ; flowers 

 greenish; anther wings nar- 

 rowed below 4. ACERATES (p. 508). 



Leaves opposite, densely tomentose 

 beneath; flowers dark purple; 

 anther wings not narrowed be- 

 low 7. GOMPHOCARPUS (p. 513). 



Hoods of the crown aristate or corniculate- 

 appendaged within. 

 Hoods short, not surpassing the stamens, 

 or if long much broader below, 



never constricted at the base. .. 5. Asclepias (p. 509). 

 Hoods long, erect, much surpassing the 

 stamens, laminately expanded 

 below, narrow at the summit, 

 mostly bicorniculate 6. Podostemma (p. 512). 



1. VINCETOXICUM Walt. Angle-pod. 



Herbaceous twining pubescent perennial from a slender rootstock; leaves opposite, 

 sagittate-cordate; flowers greenish, in small clusters; sepals lance-elliptic, green; 

 corolla narrowly campanulate, the lobes as long as the tube, oblong, obtuse; crown 

 nearly equaling the column, entire or barely undulate, inserted at the base of the 

 short column and connected with it by 5 adnate crests, free at the 2-toothed or entire 

 apex; poUinia obUquely inserted on broad winged caudicles; follicles ovoid, 3 cm. 

 long or more, puberulent. 



1. Vincetoxicum productum (Torr.) Vail, Bull. Torrey Club 26: 431. 1899. 



Gonolobus productus Torr. U. S. & Mex. Bound. Bot. 165. 1859. 



Type locality: "Banks of Rock Creek," "Valley of the Limpio, and along the 

 Rio Grande," Texas. 



Range: Western Texas to southern Arizona and southward. 



New Mexico: Organ Mountains; Mesilla Valley; Gray. Moist ground, in the 

 Lower and Upper Sonoran zones. 



2. PHILIBERTELLA Vail. 



Herbaceous twining perennials with opposite leaves and mostly fragrant flowers in 

 axillary umbels; calyx small, 5-lobed, the lobes acute; corolla campanulate or rotate, 

 a shallow entire or undulate ring forming an outer crown in its throat, the lobes 5, 

 longer than the tube, the inner crown of 5 turgid, fleshy or hard scales or flattish 

 appendages attached in a circle at the base of the sessile or slightly stalked column, 

 forming a hollow, entire or undulate, spreading surface near the level of the conical 

 stigmas; follicles naked, slender. 



KEY TO the species. 



Column conspicuous; peduncles much shorter than the crispate 



leaves; stems cinereous 1. P. crispa. 



Column inconspicuous or none; peduncles equaling or surpassing 

 the leaves, these not crispate; stems glabrous or pubescent. 

 Stems pubescent; flowers numerous in each umbel, white; 



leaves cordate-ovate to subsagittate 2. P. cynanchoides. 



Stems glabrous or nearly so; flowers few, reddish; leaves 



linear 3. P. heterophylla. 



