ARISTOLOCHIACEAE (BIRTHWORT FAMILY) 79 



A. On oaks; even the younger branches terete; leaves orbicular to spatulate, 1.2-4.2 

 cm. long, not scales, permanently villous; berry white. W. 



P. villosum (OAK MISTLETOE) 



AA. On junipers or Incense Cedar; younger branches 4-angled; leaves broadly tri- 

 angular, mere scales, ciliate; berry white or red. W. E. P. juniperinum 



ARISTOLOCHIACEAE (BIRTHWORT FAMILY) 



Herbs, with rhizome-like stem. Leaves alternate, petioled, 

 cordate or reniform; stipules none. Flowers solitary, perfect, 

 mostly large, regular. Perianth 3-lobed. Stamens 12, on the 

 ovary. Ovary wholly or partly inferior. Fruit a capsule, 6-celled. 

 Seeds many. Only the following genus. 



ASARUM (WILD GINGER) 



Rhizome ginger-like to taste, bearing several scales and 1-2 leaves. 

 Leaves entire, evergreen; petioles very long. Flowers brown-purple or 

 mottled, on long peduncles. In damp forests. (Said to be from Gk. a = 

 not, seiro = to bind ; because it withers too easily to use for garlands.) 



A. Leaves not marked with white; free tip of connective much shorter than the 

 anther; ovary about 8 mm. wide; seed 3 mm. long. W. C. E. A. caudatum 



AA. Leaves marked with white above; free tip of connective 1-2 times as long as 

 the anther; ovary about 12 mm. wide; seed 4 mm. long. W. 



A. hertwigi (MOTTLED WILD GINGER) 



POLYGONACEAE (BUCKWHEAT FAMILY) 



Herbs, or herbaceous twining vines, or shrubs; juice acid or 

 acrid. Stems plainly jointed when long enough. Leaves simple, 

 mostly entire; stipules sheathing and united, or none. Flowers 

 regular. Perianth 2-6-cleft or -parted. Stamens 2-9; filaments 

 distinct. Ovary superior, i-celled; ovule i; style 2-4-cleft or 

 -parted. Fruit an akene, lens-shaped or ^-angled or rarely 4-angled. 

 No keys to species in unimportant and difficult genera. (F. & 

 R. pp. 130-140.) 



A. Lower leaves fan-shaped, 2-lobed, distinctly toothed, 4-13 mm. long; all leaves 

 opposite, scattered along the stem. W. (Gk. pteron = a wing, stege = a cover- 

 ing; referring to the bractlike involucre inclosing the solitary flowers.) 



Pterostegia drymarioides 

 AA. Leaves never fan-shaped, not lobed, rarely faintly serrulate, often more than 



13 mm. long, alternate or whorled in almost all species, often in basal tufts. 

 B. Stipules none; flowers involucrate; juice nearly tasteless; styles 3; stamens 9. 

 C. Involucre i-flowered, coriaceous; its teeth cuspidate, often hooked; annual. 



Chorizanthe 



CC. Involucre several-flowered, either herbaceous or without sharp point to its 

 teeth. 



