APOCYNACE^. (DOGBANE FAMILY.) 393 



1. Amsoula. Seeds naked. Corolla with the tube bearded inside. Anthers longer than the 



filaments. Leaves alternate. 



2. Korst *■ ronin. Seeds comose. Corolla funnel-form, not appendaged. Filaments slen- 



der. Calyx glandular inside. Leaves opposite. 



3. A pocy ii ii in. Seeds comose. Corolla bell-shaped, appendaged within. Filaments short, 



broad and flat. Calyx not glandular. Leaves opposite. 



1. AMSONIA, Walt. Amsonia. 



Calyx 5-parted, small. Corolla with a narrow funnel-form tube bearded in- 

 side, especially at the throat ; the limb divided into 5 long linear lobes. Sta- 

 mens 5, inserted on the tube, included : anthers obtuse at both ends, longer than 

 the filaments. Ovaries 2 : style 1 : stigma rounded, surrounded with a cup-like 

 membrane. Pod (follicles) 2, long and slender, many-seeded. Seeds cylindri- 

 cal, abrupt at both ends, packed in one row, naked. — Perennial herbs, with 

 alternate leaves, and pale blue flowers in terminal panicled cymes. (Said to be 

 named for a Mr. Charles Amson.) 



1. A. Tabernsemoiltana, Walt. Loosely somewhat pubescent or hairy 

 when young, or soon glabrous ; leaves varying from ovate-lanceolate to linear- 

 lanceolate, taper-pointed ; calyx-lobes short, awl-shaped ; tube of the bluish 

 corolla little longer than the lobes, the upper part either hairy when young or 

 glabrous. — Low grounds, Illinois, Virginia? and southward. May, June. 



2. PORSTERONIA, Meyer. Forsteronia. 



Calyx 5-parted, with 3-5 glands at its base inside. Corolla funnel-form, not 

 appendaged ; the limb 5-lobed. Stamens 5, included : filaments slender : an- 

 thers arrow-shaped, with an inflexed tip, adhering to the stigma. Pods (follicles) 

 2, slender, many-seeded. Seeds oblong, with a tuft of down. — Twining plants, 

 more or less woody, with opposite leaves and small flowers, in cymes. (Named 

 for Mr. T. F. Forster, an English botanist.) 



I. F. diffbrmis, A. DC. Nearly herbaceous and glabrous; leaves oval- 

 lanceolate, pointed, thin; calyx-lobes taper-pointed; corolla pale yellow. — 

 Damp grounds, Virginia, S. Illinois, and southward. April. 



3. APOCYNUM, Tourn. Dogbane. Indian Hemp. 



Calyx 5-parted, the lobes acute. Corolla bell-shaped, 5-cleft, bearing 5 trian- 

 gular appendages in the throat opposite the lobes. Stamens 5, inserted on the 

 very base of the corolla : filaments flat, shorter than the arrow-shaped anthers, 

 which converge around the ovoid obscurely 2-lobed stigma, and are slightly ad- 

 herent to it by their inner face. Style none : stigma large, ovoid, slightly 2- 

 lobed. Fruit of 2 long and slender follicles. Seeds comose with a long tuft of 

 silky down at the apex. — Perennial herbs, with upright branching stems, oppo- 

 site mucronate-pointed leaves, a tough fibrous bark, and small and pale cymose 

 flowers on short pedicels. (An ancient name of the Dogbane, composed of 

 vivo, from, and kvo)j>, a dot/, to which the plant was thought to be poisonous.) 



1. A. androssemifblium, L. (Spreading Dogbane.) Smooth, 

 branched above; branches divergently forking ; leaves ovate, distinctly petioled ; 



