Aristolochia serpentaria
Aristolochia
Virginia snakeroot
aristoloche, birthwort, Dutchman's-pipe, pipe, pipevine
erect, twining, or procumbent.
blade lanceolate to ovate, 5-15 × 1-5 cm, base truncate to cordate, sinus depth 0-1.5 cm, apex acute to acuminate;
surfaces abaxially glabrous or hispid;
venation pinnate.
blade membranous to leathery.
from base of stem, an additional flower in axil of stem leaf, racemes;
peduncle bracteolate, to 1.5 cm;
bracteoles lanceolate, to 3 mm.
on new growth or on older stems, axillary, racemes or solitary flowers;
bracts present.
calyx brown-purple, bent;
utricle pendent, pear-shaped to ovoid, 0.5-5 cm;
syrinx present, ringlike, 1 mm, oblique;
tube bent, cylindric, 1 cm;
annulus smooth;
limb purplish brown, 3-lobed, lobes 0.5 × 0.5 cm, glabrous;
gynostemium 3-lobed, globose to crown-shaped, 1.5 mm;
anthers 6;
ovary 3-locular, to 1.5 cm.
calyx usually mixture of purple, brown, green, or red, bilaterally symmetric, tubular, usually bent or curved, 1- or 3-lobed, not fleshy, base with utricle (basal, inflated portion of calyx surrounding or containing gynostemium);
tube narrowed, sometimes extended proximally as cylindric syrinx (tubular or ringlike structure at juncture of tube and utricle, projecting into utricle cavity) and distally as annulus (circular flange at juncture of tube and limb) on limb;
corolla absent;
stamens 5-6, adnate to styles and stigmas, forming gynostemium;
ovary inferior, 3-, 5-, or 6-locular;
styles 3, 5, or 6, connate in column.
globose, 0.8-2 × 1-2 cm, dehiscence basipetal;
valves 6;
septa absent.
dry, dehiscent.
rounded, ovate, 0.5 × 0.4 cm.
flattened or rounded, sometimes winged.
= 6, 7, 8.
= 28.
Aristolochia serpentaria
Aristolochia
Inflorescences of Aristolochia serpentaria often bear closed flowers that appear to be cleistogamous. Leaf shape varies greatly between populations, especially with regard to leaf width and size of basal lobes. This variability is especially interesting because eastern pipe-vine swallowtail butterflies, Battus philenor philenor (Linnaeus), use leaf shape as a search image when looking for Aristolochia leaves on which to lay their eggs.
The dried rhizome, called Virginia snakeroot or serpentary, is a popular herbal tonic. In small doses, it is a gastric stimulant and diuretic. Large doses can cause violent gastric distress and respiratory paralysis (J. A. Duke 1985). The rhizome contains aristolochic acid and trimethyl amine, both potential carcinogens.
Several Native American tribes used Aristolochia serpentaria for diverse medicinal purposes, including treatment of rheumatism, various pains, obstructions, worms, toothaches, sore throats, fever, sore noses, and colds, as a tonic, and mixed with saliva for snake bites (D. E. Moerman 1986).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Species ca. 300 (12 in the flora).
Most European and tropical species of Aristolochia are believed to be pollinated by small flies attracted to the flowers by the fetid odors and purple-brown color. Flies enter the flower when the stigmas are receptive and are trapped until after the anthers dehisce (H. Solereder 1889, 1889b). No formal studies of pollination of the North American species have been reported.
Many species of Aristolochia have been used in the treatment of snakebite; the treatment may or may not be effective. All species contain aristolochic acid, which is variously reported as tumor-causing or tumor-inhibiting (J. A. Duke 1985).
The leaves of many species are eaten by pipe-vine swallowtail butterflies. The larvae eat leaves of these species and sequester aristolochic acid in their bodies, making them unpalatable to birds (W. H. Howe 1975).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Leaf base attentuate, cuneate, or truncate (truncate to slightly cordate in A. maxima). | → 2 |
1. Leaf base cordate, auriculate, sagittate, or hastate. | → 4 |
2. Woody lianas; peduncle not bracteolate; capsule 4-7 cm wide, dehiscence acropetal; syrinx absent. | A. maxima |
2. Herbs; peduncle bracteolate; capsule 1-3 cm wide, dehiscence basipetal; syrinx present. | → 3 |
3. Inflorescences on new growth, axillary, solitary flowers; utricle ovoid to obconic; gynostemium 5-lobed; capsule ovoid. | A. erecta |
3. Inflorescences from base of stem, racemes; utricle pear-shaped to ovoid; gynostemium 3-lobed; capsule globose. | A. serpentaria |
4. Lianas. | → 5 |
4. Herbs. | → 8 |
5. Leaf venation palmate; calyx limb 1-lobed; young stem smooth; syrinx present; gynostemium 5-lobed. | A. pentandra |
5. Leaf venation pinnate or palmate-pinnate; calyx limb 3-lobed; young stem ribbed; syrinx absent; gynostemium 3- or 6-lobed. | → 6 |
6. Leaf sinus 2-6 cm deep; capsule 1-3 cm wide; gynostemium 5-10 mm. | A. californica |
6. Leaf sinus 1-4.5 cm deep; capsule 4-10 cm wide; gynostemium 1-4 mm. | → 7 |
7. Stem and leaf glabrous or puberulent; peduncle bracteolate; utricle globose to cylindric; annulus smooth. | A. macrophylla |
7. Stem tomentose; leaves abaxially tomentose; peduncle not bracteolate; utricle globose to cylindric; annulus rugulose. | A. tomentosa |
8. Leaf venation palmate; leaf blade as wide as long or wider. | → 9 |
8. Leaf venation pinnate or palmate-pinnate; leaf blade longer than wide. | → 11 |
9. Petiole 4-7 cm; stem erect; peduncle not bracteolate; gynostemium 3-lobed; young stem ribbed. | A. clematitis |
9. Petiole 1-3 cm (to 4 cm in A. coryi); stem procumbent; peduncle bracteolate; gynostemium 5-lobed; young stem smooth or slightly striate. | → 10 |
10. Stem and leaf velutinous with yellowish trichomes; leaf blade ovoid to hastate, (0-)3-lobed; calyx brown-purple, straight; gynostemium ovoid. | A. wrightii |
10. Stem and leaf glabrous or puberulent; leaf blade deltate, not 3-lobed; calyx yellow-green or yellow-brown, curved; gynostemium crown-shaped. | A. coryi |
11. Leaf apex obtuse or rounded; gynostemium 5-10 mm; syrinx indistinct or absent. | A. reticulata |
11. Leaf apex acuminate or acute; gynostemium 1-4 mm; syrinx present. | → 12 |
12. Calyx limb 1-lobed; inflorescences on new growth, axillary, solitary flowers; utricle ovoid to narrowly ellipsoid; gynostemium 5-lobed; capsule ovoid to obovoid; annulus absent on calyx limb. | A. watsonii |
12. Calyx limb 3-lobed; inflorescences from base of stem, rarely an additional flower in axil of stem leaf, racemes; utricle pear-shaped to ovoid; gynostemium 3-lobed; capsule globose; annulus present on calyx limb, smooth. | A. serpentaria |
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