282 BIRTH WORT FAMILY. 



III. APETALOUS DIVISION. Includes the orders with 

 flowers destitute of corolla ; some are destitute of calyx also. 



90. ARISTOLOCHICAE^I, BIRTHWORT FAMILY. 



Known from all other apetalous orders by the numerous ovules 

 and seeds in a 6-celled ovary, to which the lower part of the calyx 

 is adherent, the latter mostly 3-lobed, the stamens generally 6 or 

 12. Anthers adnate and turned outwards. Calyx dull-colored, 

 valvate in the bud. Leaves petioled, usually heart-shaped, not 

 serrate. Flowers solitary, perfect, commonly large. Bitter, tonic 

 or stimulant, sometimes aromatic plants. 



1. ASARUM. Low stemless herbs, with one or two leaves on long petioles, and a 



flower -at the end of a creeping aromatic rootstock, the flowers therefore 

 close to the ground. Calyx regular, with 3 equal lobes. Stamens 12, dis- 

 tinct, borne on the apex of the ovary or the base of the stout style, usually 

 pointed beyond the anther. Seeds large, thickish, in a rather fleshy ana 1 

 irregularly bursting pod. 



2. ARISTOLOCHIA. Leafy-stemmed herbs or woody twiners. Calyx tubular 



variously irregular, often curved. Filaments none : anthers adherent directly 

 and by their whole inner face to the outside of the 3 - 6-lobed stigma. Seeds 

 very flat, in a dry 6-valved pod. 



1. ASARUM, AS ARAB A CCA, WILD GINGER. (Ancient name, of 

 obscure derivation.) On hillsides in rich woods : fl. spring. ^ 



1 . Filaments slender, much longer than the short anthers : style 1 , thick, bearing 

 6 thick stigmas : leaves a single pair with a peduncle between them. 



A. Canadense, CANADA WILD GINGER, sometimes called SNAKEROOT. 

 Common N. : soft-pubescent ; leaves broadly heart-shaped or kidney-shaped, not 

 evergreen ; calyx bell- shaped but cleft down to the adherent ovary, brown- 

 purple inside, the abruptly spreading lobes pointed. 



2. Filaments short or almost none : anthers oblong-linear : styles 6, each 2-cleft, 

 bearing the stigma bf-low the cleft : haves thick and evergreen, siitooth, often 

 mottled, usually only one each year : rootsfocks in a close cluster. 



A. Virginicum, VIRGINIA AV. Along the Alleghanies S. : leaves small, 

 rounded heart-shaped ; calyx tubular-bell-shaped with a somewhat narrowed 

 throat and broad short lobes, the base coherent only with base of the ovary. 



A. arifblium, from Virginia S , has larger somewhat halberd-shaped 

 leaves, and very short and blunt lobes to the calyx. 



2. ARISTOLOCHIA, BIRTHWORT. (Ancient name, from medicinal 

 properties.) Cells of the anthers in our species 4 in a horizontal row under 

 each of the 3 lobes of the stigma, i. e. two contiguous 2-celled anthers in each 

 set, or 6 in all. Flowers in and above the axils. 



A. Serpentaria, VIRGINIA SNAKEROOT (used in medicine). Rich woods, 

 chiefly in Middle States and S. : low downy herb ; stems clustered about 1 

 high ; leaves ovate or oblong and heart-shaped, sometimes halberd-form, acute ; 

 flowers all next the root, curved like the letter S, contracted in the middle and 

 at the throat, in summer. ^ 



A. Sipho, PIPE- VINE, DUTCHMAN'S PIPE (from the shape of the curved 

 calyx). Rich woods from Penn. along the mountains S. and planted for arbors : 

 very tall-climbing woody twiner, smooth, but the rounded heart-shaped leaves 

 often downy beneath, these becoming 8' -12' broad ; peduncles with a clasping 

 bract, drooping; calyx l' long, inflated above the ovary, narrowing above, 

 contracted at the throat, the flat border brown-purple and obscurely 3-lobed : 

 fl. late spring. 



A. tomentosa. Common S. : a more slender woody climber, with smaller 

 rounder and very veiny downy leaves, and yellowish flower with an oblique 

 almost closed brownish orifice, the border reflexed : fl. late spring or summer. 



