258 SYSTEMATIC BOTANY. 



Pistillate flowers calyx and corolla as in the staminate ; style single ; 

 stigma 2-cleft. Fruit a i-2-celled samara, flattened; winged at apex. 

 Trees. 



1. F. AMERICANA (White AsK). Leaflets 7-9, petiolate, oblong or ob- 

 long-ovate, acuminate, glaucous beneath, mostly smooth ; calyx present ; 

 corolla wanting ; fertile flowers in loose panicles ; the barren in dense, con- 

 tracted ones ; samara obtuse, narrow, spatulate, with a long, tapering base. 

 April-May. 



2. F. PUBESCENS (Red AsK). Leaflets 7-9, petiolate, lanceolate or lance- 

 ovate, soft-downy ; calyx present ; corolla wanting ; samara obtuse, abruptly 

 tapering at base. April-May. 



3. F. SAMBUCIFOLIA (Black Ask). Leaflets 7-11, sessile, ovate-lanceo- 

 late, serrate, hairy on the veins beneath ; calyx and corolla both wanting ; 

 samara oblong, extremely obtuse at both ends. In moist woods and swamps. 

 May. 



Order LI. APOCYNACE^E (Dogbane Family). 



Trees, shrubs, or herbs, with a milky juice. Leaves opposite, 

 or verticillate, rarely alternate, without stipules. Flowers regular. 

 Sepals 5, united, persistent. Corolla 5-lobed, twisted in preflora- 

 tion. Stamens 5, alternate with the segments of the corolla. 

 Filaments distinct. Anthers 2-celled, sometimes slightly con- 

 nected. Ovaries 2, distinct, rarely united, but with 2 united styles 

 or stigmas. Fruit usually a pair of follicles, I sometimes abortive. 

 Seeds often with a coma, or tuft of hairs. 



C Shrubs Nerium. 



APOCYNACFJE. f Upright herbs _^,^ 



[ Herbs \ 



[ Trailing or creeping Vinca. 



I. Apocynum. Calyx very small, 5-parted. Corolla campanulate, 

 with 5 short lobes. Stamens 5, inserted at the base of the corolla. 

 Anthers sagittate, converging, much longer than the very short fila- 

 ments. Stigma ovoid, obscurely 2-lobed. Fruit 2 long, slender fol- 

 licles. 



1. A. ANDROS.^MIFOLIUM (Dog's-bane). Smooth ; stem erect, branch- 

 ing above, reddened by the sun on one side, with diverging, forked branches ; 

 leaves ovate, entire ; flowers in loose cymes ; corolla white, striped with rose- 

 color, with 5 acute, revolute segments ; follicles 2 '-3' long, nodding. In 

 thickets, 2-3 feet high. June- July. 2f 



2. A. CANNABINUM (Indian Hemp). Stem erect, dividing above into 

 long, ascending branches ; leaves oblong; flowers very small, greenish-white, 

 in dense, erect, many-flowered cymes, shorter than the leaves ; corolla-lobes 

 nearly erect, the tube scarcely longer than the lanceolate calyx-teeth. In 

 thickets, 2-3 feet high. June-July. 



