539 



Large- tl.. irum. 





BIRTHWORT FAMILY. 



3. Asarum macranthum (Shutthv.) Small. 



(Fig. 1279.) 



Homotropa macranthum Shutthv.; Small Mem 



Torr. Club, 4: 150, as synonym. 1894 

 Asarum macranthum Small, Mem. Torr Club 



5: 136. 1894. 



Glabrous, rootstocks more or less branched. 

 Leaves i or 2 to each plant or branch, 

 broadly ovate or suborbicular, dark green 

 and usually mottled above, paler beneath, 

 2'-4' long, 1%'-$' wide, obtuse or subacute 

 at the apex, the basal sinus mostly narrow- 

 petioles 3'-8' long, ascending; calyx tubular- 

 campanulate, 8 // -2o // long, not or scarcely 

 contracted at the throat, the lobes somewhat 

 unequal, obtuse, mottled with violet on the 

 inner side, one-third to one-half as long as 

 the tube; peduncle 8" -20" long; filaments 

 shorter than the anthers; anthers equally 4- 

 ribbed, not pointed; styles 6, each 2-cleft. 



In rich mountain woods, Virginia and North 

 Carolina. May-July. 



4. Asarum arifdlium Michx. HalU-rd- 

 leaved Asarum. (Fig. 1280.) 



A. at (folium Michx. Fl. Bor. Am. I: 779. 1803. 



Pubescent, at least on the veins of the leaves, 

 rootstocks slender, usually branched and with 

 i or 2 leaves to each branch. Leaves rather 

 thick, usually mottled, obtuse at the apex, 2'-$' 

 long, some of them hastate, some suborbicular, 

 the basal sinus often broad; petioles more or 

 less pubescent, 3'-8' long, erect or ascending; 

 flower stout-peduncled, about i' long; calyx 

 urn-shaped, much contracted at the throat, the 

 lobes rounded, about one-fifth as long as the 

 tube, which is adnate to the lower half of the 

 ovary; anthers nearly sessile, short-pointed; 

 styles 6, 2-cleft, with a sessile stigma below the 

 cleft; capsule subglobose, about S" in diameter. 



In \\oods. Virginia to Tennessee, Florida and 

 Alabama. Ascends to 3000 ft. in Virginia 

 June. 



2. ARISTOLOCHIA L. Sp. PI. 960. 1753. 



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

 exotic species 3-7-lobed), cordate, palmately 3-many-nervcd. 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 st> 

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

 some 6 others occur in the southern and western United States. 



Erect herbs. 



Calyx-tube bent; flowers solitary, on basal scaly branches. i .4 St 



Calyx-tube straight: flowers axillary, cluttered. 2. A. Of mat ids. 



Tall twining vines; flowers axillary; calyx-tube bent 



Leaves minutely pubescent: calyx-limb flat, spreading, vlla. 



Leaves tomentose ; calyx-limb rugose, refK 



