ARISTOLOCHIACE^B. (BIRTH WORT FAMILY.) 359 



DIVISION III. APETALOUS EX6GENOUS PLANTS. 



Corolla none ; the floral envelopes in a single series (calyx), of 

 sometimes wanting altogether. 



ORDER 87. ARISTOLOCHIACE^E. (BIRTHWORT FAM.) 



Climbing shrubs, or low herbs, with perfect flowers, the conspicuous lurid 

 calyx (yalvate in the bud) coherent below with the 6-celled ovary, which forms 

 a many-seeded 6-celled pod or berry in fruit. Stamens 6-12, more or less 

 united with the style: anthers adnate, extrorse. Leaves petioled, mostly 

 heart-shaped and entire. Seeds anatropous, with a large fleshy raphe, and 

 a minute embryo in fleshy albumen. 



1. AS ARUM, Tourn. ASARABACCA. WILD GINGER. 



Calyx regular; the limb 3-cleft or parted. Stamens 12, with more or less 

 distinct filaments, their tips usually continued beyond the anther into a point. 

 Fruit fleshy, globular, bursting irregularly. Stemless herbs with aromatic- 

 pungent creeping rootstocks bearing 2-3 kidney-shaped or heart-shaped leaves 

 on long petioles, and a short-peduncled flower close to the ground. (An ancient 

 name, of obscure derivation.) 



$ 1. AS&llUM PROPER. Calyx-tube wholly coherent with the ovary : filaments 

 slender, united only with the base of the style, much longer than the short anthers : 

 styles united into one, which is barely b-lobed at the summit, and with 6 radiating 

 thick stigmas : leaves membranaceous, unspotted, on flowering stems mostly a single 

 pair, with the peduncle between them. 



1. A. Caiiadense, L. Soft-pubescent; leaves kidney-shaped, more or 

 less pointed (4' -5' wide when full grown) ; calyx bell-shaped, with the upper 

 part of the acute lobes widely and abruptly spreading, brown-purple inside ; 

 stamens awn-tipped. Hill-sides in rich woods ; common, especially northward, 

 and along the Alleghanies. April, May. 



$ 2. HETER6TROPA. Calyx-tube somewhat inflated below and contracted at 

 the throat, only its base coherent with the lower part of the ovary ; the limb 3-cleft, 

 short : filaments very short or none: anthers oblong-linear: styles 6, fleshy, diverging, 

 2-cleft, each bearing a thick extrorse stigma below the cleft : leaves thickish, per- 

 sistent, the upper surface often whitish-mottled, alternate on the rootstock : peduncle 

 very short. 



2. A. Virginicum, L. Leaves round-heart-shaped (l%'-2' wide) ; calyx 

 ventricose-bell-shaped ; anthers pointless. Virginia, and southward, in and near 

 the mountains. May. 



3. A. ari folium, Michx. Leaves halberd-heart-shaped (2' -4' long), 

 calyx oblong-tubular, with very short and blunt lobes; anthers obtusely short- 

 j.fointed. Virginia, and southward. May. 



