GENUS 3. 



BIRTHWORT FAMILY. 



6 45 



3. ARISTOLOCHIA (Tourn.) L. Sp. PI. 960. 1753. 



Perennial herbs or twining vines. Leaves alternate, mostly petioled and entire (some 

 exotic species 3-7-lobed), cordate, palmately 3-many-nerved. Flowers irregular, solitary or 

 clustered. Calyx adnate to the ovary, at least to its base, the tube narrow, usually inflated 

 around the style and contracted at the throat, the limb spreading or reflexed, entire, 3-6- 

 lobed or appendaged. Stamens mostly 6; anthers sessile, adnate to the short style or 

 stigma, 2-celled, the sacs longitudinally dehiscent. Ovary partly or wholly inferior, mostly 

 6-celled with 6 parietal placentae. Style 3-6-lobed. Capsule naked, septicidally 6-valved. 

 Seeds very numerous, horizontal, compressed, their sides flat or concave. [Named for its 

 supposed medicinal properties.] 



About 200 species, widely distributed in tropical and temperate regions. Besides the following, 

 some 6 others occur in the southern and western United States. Type species : Aristolochia rotunda L. 



Erect herbs. 



Calyx-tube bent ; flowers solitary, on basal scaly branches. i. A. Serpentaria. 



Calyx-tube straight ; flowers axillary, clustered. 2. A, Clematitis. 

 Long twining vines ; flowers axillary ; calyx-tube bent. 



Leaves minutely pubescent ; calyx-limb flat, spreading. 3. A. macrophylla. 



Leaves tomentose ; calyx-limb rugose, reflexed. 4. A. tomentosa. 



i. Aristolochia Serpentaria L. Virginia Snakeroot. Serpentary. Fig. 1578. 



Aristolochia Serpentaria L. Sp. PI. 961. 1753. 



A perennial pubescent nearly erect herb, io'-3 

 tall, with short rootstocks and fibrous aromatic 

 roots. Leaves ovate, ovate-lanceolate or oblong- 

 lanceolate, thin, green on both sides, acuminate at 

 the apex, cordate or hastate at the base, ii'-5' long, 

 i'-2' wide ; petioles J'-i' long ; lowest leaves reduced 

 to scales ; flowers solitary and terminal, on slender 

 basal scaly branches ; tube of the calyx curved like 

 the letter S, enlarged at the ovary and at its throat, 

 the limb short, spreading, slightly 3-lobed ; anthers 

 contiguous in pairs ; stigma 3-lobed ; capsule subglo- 

 bose, ridged, about i' in diameter. Flowers some- 

 times cleistogamous. 



In dry woods, Connecticut and New York to Michigan, 

 Florida, Louisiana and Missouri. Ascends to 2500 ft. in 

 Virginia. June-July. Fruit ripe Sept. Sangrel snake- 

 weed. Sangree-root. Black snakeroot. Pellican-flower. 



Aristolochia hastata Nutt. (A. Nashii Kearney, of the 

 southern states), with narrowly lanceolate or linear, sag- 

 ittate or hastate leaves, is reported to range as far north 

 as Virginia. 



2. Aristolochia Clematitis L. Birth- 

 wort. Fig. 1579. 



Aristolochia Clematitis L. Sp. PI. 962. 1753. 



Herbaceous, perennial ; stem erect, glabrous, 

 zigzag, striate, i-2 tall. Leaves dark green, 

 reniform, subacute or obtuse at the apex, gla- 

 brous or their margins minutely spinulose- 

 ciliate, strongly reticulate-veined, 2'-$' wide ; 

 petioles shorter than the blades ; flowers fas- 

 cicled in the axils, i'-ij' long; tube of the 

 calyx yellowish green, straight, enlarged 

 around the ovary, the 6 lobes appendaged; 

 anthers equidistant. 



Roadsides and thickets, New York to Maryland. 

 Escaped from cultivation. Native of southern 

 Europe. Summer. Upright birthwort. 



