A RIS TOLO CHI A CEA E. 3 49 



when young- Leaf-blades very thin, reniform-cordate, and acutely short-pointed 

 or broadly reniform and blunt, densely cinereous-tomentulose beneath, less closely 

 so in age, the larger nerves often somewhat bristly, thus giving the lower surfaces 

 a white-reticulated aspect; calyx-segments much longer than those of A. Canadense 

 and of a duller brownish purple color, caudate-acuminate or flagellate, the tubular 

 terminations 10-20 mm. long, recurved-spreading. In rich woods, Minn, and 

 Wis. to Manitoba, Ind. and Ohio. May-June. 



3. Asarum refiexum Bicknell. Short-LOBED Wild Ginger. (I. F. f. 

 1277^.) Similar to the two preceding species in habit, but more loosely pubescent 

 and with more elongated and slender rootstocks; leaf-blades renitorm, much 

 broader than lung, blunt-tipped, the upper surface and the petioles nearly glabrous 

 in age; calyx much smaller, the tube white within, the segments early reflexed, 

 triangular, purplish brown, about as long as the tube, with a straight obtuse tip 

 2-4 mm. long. In rich woods, along streams and in river valleys, Conn, to Iowa, 

 N. C, Mo. and Kan. April-May. 



Asarum refiexum ambiguum Bicknell. Leaf-blades short and conspicuously broad, 

 with a wide and often rectangular sinus ; calyx-segments narrower and longer, 12-19 

 mm. long, the straight tip 4-S mm. long, sometimes extending back to the base of the 

 ovary. Mich., 111. and Mo. 



3. ARISTOLOCHIA U] 



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

 (some exotic species 3-7-lobed), cordate, palmately nerved. Flowers irregular. 

 Calyx adnate to the ovary, at least to its base, the tube 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 adnate to the short style or 

 stigma, 2 -celled, the sacs longitudinally dehiscent. Ovary mostly 6-celled with 

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

 Seeds very numerous, horizontal, compressed. [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. 



Leaves hastate at the base ; capsules 5-6 mm. in diameter. 1. A. Nashii. 

 Leaves merely cordate at the base ; capsules about 10 mm. in diameter. 



2. A. Serpentaria. 

 Calyx-tube straight ; flowers axillary, clustered. 3. A. Clematitis. 



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



Leaves minutely pubescent ; calyx-limb flat, spreading. 4. A. macrophylla. 



Leaves tomentose ; calyx-limb rugose, reflexed. 5. A. tomentosa. 



1. Aristolochia Nashii Kearney. Nash's Snakeroot. Stems erect or re- 

 clining. 1-3 dm. long, zigzag, simple or branched below; leaves thin, linear or 

 linear-lanceolate above the hastate base, 2-10 cm. long, acuminate, ciliate, short- 

 petioled; peduncles slender; bracts 2-4 mm. long; calyx S- shaped, brownish purple, 

 10-12 mm. long, the limb slightly 3-lobed, about I cm. broad; capsules subglobose, 

 5-6 mm. in diameter, sharply angled. In damp woods, Va. to Fla. and La. 

 Summer. 



2. Aristolochia Serpentaria L. Virginia Snakeroot. Serpentary. 

 (I. F. f. 1281.) Stems erect, 2-5 dm. tall, sometimes branched below, more or less 

 zigzag; leaves rather thin, oblong-lanceolate to ovate or oval-lanceolate, 4-15 cm. 

 long, acuminate, undulate, cordate, short-petioled; peduncles scaly, solitary or 

 clustered; bracts 2-3 mm. long; calyx S-shaped, about 1 cm. long, the limb slightly 

 3-lobed; capsules subglobose. about 10 mm. in diameter, somewhat ribbed; flowers 

 sometimes cleistogamous. In dry woods. Conn, and N. Y. to Mich., south to Fla. 

 and La. Summer. 



3. Aristolochia Clematitis L. Birthwort. (I. F. f. 1282.) Stem erect, 

 glabrous, zigzag, 3-6 dm. tall; leaves dark green, reniform, glabrous, or their 

 margins minutely spinulose-ciliate. strongly reticulate-veined. 5— 13 cm. wide; peti- 

 oles shorter than the blades; flowers fascicled in the axils, 2.5-3.5 cm - l° n g5 tuDe 



