194 APOCYNACEAE. 



286. MENYANTHES. Buckbean. 



Perennial herbs, with thick creeping rootstocks sheathed by 

 the membranous bases of the petioles ; leaves trifoliolate ;_ calyx 

 5-parted; corolla funnelform, 5-cleft; style slender, persistent; 

 stigma 2-lobed; capsule bursting irregularly, many-seeded. 



Menyanthes trifoliata L. Perennial from scaly rootstocks; leaves tri- 

 foliolate, the petioles sheathing at base; leaflets oblong to obovate, entire, 

 obtuse; peduncles stout; racemes 10-20-flowered; corolla white or rose-tinged, 

 its lobes bearded above; capsule ovoid. In bogs near Troy and Spokane and 

 about Rock Lake and Lake Pend Oreille. 



Family 72. APOCYNACEAE. 



Herbs (in ours) with acrid milky juice; leaves entire, opposite, 

 without stipules; flowers regular; calyx free from the ovaries; 

 corolla gamopetalous, 5-lobed; stamens 5, alternate with the 

 corolla-lobes, epipetalous; pistils of two carpels, the ovaries 

 separate (in ours), the styles or stigmas united; fruit a pair of 

 follicles; seeds many, often downy- tufted at the apices; endo- 

 sperm not copious. 



287. APOCYNUM. Dogbane. 



Perennial herbs; leaves opposite, mucronate-pointed ; flowers 

 small, in cymes, on short pedicels ; calyx 5-parted, the lobes acute ; 

 corolla bell-shaped, 5-cleft, bearing 5 triangular appendages 

 below the throat, opposite the lobes; stamens 5, on the very base 

 of the corolla; fruit of two long and slender follicles; seed with a 

 tuft of long silky down at the apex. 



Corolla lobes revolute; leaves ovate. A. pumilum. 

 Corolla lobes erect; leaves lanceolate to oblong. 



Calyx and bracts ciliolate. A. ciliolaium. 



Calyx and bracts entire. A. cannahinum. 



Apocynum pumilum (Gray) Greene. Much branched from the base, 30-40 

 cm. high ; branches erect or ascending, glabrous throughout or rarely puberulent, 

 usually very floriferous; leaves ovate, cuspidate, 1-4 cm. long, dark-green 

 above, pale beneath, short-petioled ; flowers rose-colored; calyx-lobes about 

 equalling the tube; corolla 5-6 mm. long, the lobes reflexed; pod 6-8 cm. long, 

 spreading or reflexed. Common on hills, difficult to eradicate and sometimes 

 a troublesome weed. A puberulent prostrate form which may be distinct 

 occurs in open pine woods, in the Thatuna Hills, Idaho. 



Apocynum ciliolatum Piper. Stems erect, very leafy, branched above, 

 60-70 cm. high, glabrous; leaves elliptic or elliptic-lanceolate, puberulent on 

 both sides, 4-7 cm. long, 2-3 cm. wide, nearly sessile; panicle ample, rather 

 loose, its branches erect, glabrous; bracts lanceolate, ciliate; pedicels pubescent; 

 calyx lobes deltoid, acute, erect, ciliolate, shorter than the corolla tube; corolla 

 pink, 5 mm. long, the erect lanceolate acutish ciliolate lobes as long as the tube, 

 which is nearly glabrous within. Wawawai. 



