apocynace^e. (dogbane family.; 349 



Order 84. APOCYNACEiE. (Dogbane Family.) 



Plants with milky acrid juice, entire (chiefly opposite) leaves without sti- 

 pules, regular b-merous and 5-androus flowers ; the 5 lobes of the corolla 

 convolute and twisted in the bud; the filaments distinct, inserted on the corolla, 

 and the pollen granular ; the calyx entirely free from the two ovaries, which 

 are usually quite distinct (and forming pods), though their styles or stig- 

 mas are united into one. — Seeds amphitropous or anatropous, with a large 

 straight embryo in sparing albumen, often bearing a tuft of down (comose). 

 — Chiefly a tropical family (of acrid-poisonous plants), represented in our 

 district by three genera. 



Synopsis. 



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



filaments Leaves alternate 



2. FORSTERONIA. Seeds comose. Corolla funnel-form, not appendaged. Filaments slen- 



der. Calyx glandular inside. Leaves opposite. 

 R. APOCYNUM. Seeds comose. Corolla bell-shaped, appendaged within. Filaments short, 

 broad, and fiat. 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. Pods (follicles) 2, long and slender, many-seeded. Seeds cylindri- 

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

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

 named for a Mr. Charles Amson.) 



1. A. TabernaeniOBitfina, Walt. Leaves ovate-lanceolate, rather 

 obtuse at the base, short-petioled ; tube of the corolla above hairy outside. (A. 

 latifolia, Michx.) — Damp grounds, Illinois (Mead, &c), Virginia"? and south- 

 ward. May. 



A. ciliA.ta, with linear leaves, and A. salicif6lia, with lanceolate leaves 

 may be expected in Virginia and Illinois. 



2. FOBSTEHONIA, Meyer. Forsteronia. 



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

 appendaged ; the limb 5-lobed. Stamens 5, inserted on the base of the corolla, 

 included : filaments slender : anthers arrow-shaped, with an indexed tip, adher- 

 ing to the stigma. Pods (follicles) 2, slendev, 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. ) 



1. F. diflorimis, A. DC. Nearly herbaceous and glabrous ; leaves oval- 

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



