392 ARISTOLOCHIACE^E. (filRTHWORT FAMILY.) 



opening irregularly. Aromatic perennial herbs, with creeping stems, long- 

 petioled cordate or kidney-shaped leaves, and axillary peduucled flowers. 

 1. ASARUM. Calyx bell-shaped, adnate to the ovary, 3-parted : filaments 

 free or nearly so: stiyma 6-lobed. Leaves deciduous. 



1. A. Canadense, L. (WILD GINGER-ROOT.) Pubescent; leaves 2, 

 kidney-shaped ; calyx lobes acuminate ; filaments as long as the style. 

 Mountains of North Carolina, and northward. April - May. Flowers short- 

 peduucled, purple within. 



2. HETEROTROPA. Calyx inflated, marl y free from the orary, 3-cleft: fila- 

 ments united with the ovary: styles 6: stigma 2-cleft. Leaves evergreen, 

 smooth, mottled. 



2. A. Virginicum, L. Leaves round-cordate; calyx inflated-bell- 

 shaped, with rounded lobes; stigmas deeply 2-clcft. Rich shady woods in 

 the upper districts. April -May. Leaves single or 2-3 together, 2' long. 

 Calyx 8" -9" long, nearly sessile at the base of the petioles, greenish with- 

 out, dull purple within. 



3. A. arifolium, Michx. Leaves oblong-cordate or hastate ; calyx pitcher- 

 shaped, with rounded lobes ; stigmas slightly 2-cleft. Shady woods. March - 

 April. Leaves 3' -4' long, auriculate at the base, loug-petiok'd. Calyx I' 

 long, distinctly peduncled, contracted above the middle, dark purple within. 



2. ARISTOLOCHIA, Tourn. BIRTIIWOKT. 



Calyx tubular, commonly bent and inflated above the ovary. Anthers 5-6, 

 sessile, adnate to the 3 - 6-lobed or angled stigma. Capsule 5 - 6-valved. 

 Erect or twining herbs or shrubs. Leaves alternate, cordate at the base. 

 Flowers long-peduncled, axillary, or near the base of the stem. 



* Stamens 6. 



i Low herbs. 



1. A. Serpentaria, L. (SNAKEROOT.) Stems single or clustered, pu- 

 bescent, zigzag and leafy above; leaves short-petioled, varying from ovate to 

 linear-lanceolate, cordate or hastate at the base ; flowers near the base of the 

 stem, on braeted spreading peduncles; calyx tortuous, 3-lobed, dull purple. 

 Shady woods. June -August. Stem 8'- 12' high. Leaves 2' -4' long. 

 Calyx shaped like the letter S. 



*- -t- Woody vines: capsule oblong, 6-anrjled, 3' -4' long. 



2. A. Sipho, L'Her. Stem smoothish ; leaves large, orbicular-cordate, 

 slightly pubescent beneath ; peduncles slender, solitary, with a roundish clasp- 

 ing bract near the base ; calyx curving upward, with the broad spreading 

 brownish purple border obscurely 3-lobed. Rich woods along the mountains. 

 May. Stem climbing high. Leaves 6' -12' broad. Calyx shaped like a Dutch 

 pipe, 1$' long. 



3. A. tomentosa, Sims. Hoary-pubescent ; leaves cordate ; peduncles 

 opposite the leaves, bractless, woolly ; calyx bent in the middle, the greenish 

 rugose unequally 3-lobed border reflexed, thickened and dark brown at the 

 nearly closed throat. River banks, chiefly in the upper districts. May. 

 Stem very long. Leaves 3' -5' long. Calyx similar in shape to the preced- 

 ing, but smaller. 



