ARISTOLOCHIACE^E. (BIRTHWORT FAMILY.) 403 



DIVISION El. APETALOUS EX6GENOUS PLANTS. 



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

 sometimes wanting altogether. 



ORDER 82. ARISTOL-OCHIACE^E. (BIRTHWORT FAMILY.) 



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

 calyx valvate in the bud and coherent (at least at the base) with the 6-celled 

 ovary, which forms a many-seeded ^-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 rhaphe, and a minute embryo in fleshy albumen. A small family of 

 bitter-tonic or stimulant, sometimes aromatic plants. 



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. 

 Pod rather fleshy, globular, bursting irregularly. Seeds large, thick. Stem- 

 less herbs, with aromatic-pungent creeping rootstocks, bearing 2 or 3 scales, then 

 one or two kidney-shaped or heart-shaped leaves on long petioles, and termi- 

 nated by a short-peduncled flower, close to the ground ; in spring. (An ancient 

 name, of obscure derivation. ) 



1. Calyx-tube wholly coherent with the ovary, the tips inflexed in bud: filaments 

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

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

 thick stigmas : leaves unspotted, a single pair, with the peduncle between them. 



1. A. Canad6nse, L. Soft-pubescent; leaves membranaceous, kidney- 

 shaped, more or less pointed (4' - 5' wide when full grown) ; calyx bell-shaped, 

 with the upper part of the short-pointed lobes widely and abruptly spreading, 

 brown-purple inside; at each sinus is usually a small awl-shaped appendage 

 (abortive petal). Hillsides in rich woods : common, especially northward. 



2. Calyx-tube inflated bell-shaped, somewhat contracted at the throat, only its base 

 coherent with the lower half of the ovary ; the limb 3-cleft, short : filaments very 

 short or none : anthers oblong-linear : styles 6, fleshy, diverging, 2-cleft, each bear- 

 ing a thick extrorse stigma below the cleft : leaves thickish, persistent, usually only 

 one each year, the upper surface often whitish-mottled : peduncle very short : root- 

 stocks clustered, ascending. 



2. A. Virginiciim, L. Nearly glabrous ; feaves round-heart-shaped ( about 

 2' wide) ; calyx short, reticulated- within ; anthers pointless. Virginia, and 

 southward, in and near the mountains. 



3. A. arifdlium, Michx. Leaves halberd-heart-shaped (2' -4' long); calyx 

 oblong-tubular, with very short and' blunt lobes ; anthers obtusely short-pointed. 

 Virginia and southward. 



