ARISTOLOCHIACE. 89 
EXCLUDED SPECIES. 
THESIUM INTERMEDIUM. Schrad. 
“May be a native of Britain.” (Bab. Man. Brit. Bot. ed. vi. 
p- 298). I have seen no specimens, nor can I hear of anyone 
who has. 
THESIUM HUMILE. Jail. 
Professor Babington gathered two specimens of this plant somewhere 
near Dawlish in Devonshire, in 1829, but it was probably not indi- 
genous. 
ORDER LXVI—ARISTOLOCHIACES. 
Herbs or shrubs, in the latter case generally twining, and with the 
wood not in evident rings. Leaves alternate, sometimes 2 and sub- 
opposite, stalked, generally cordate, entire, rarely pedatifid. Stipules 
opposite the leaves, or leafy or absent. Flowers perfect, rarely uni- 
sexual, solitary or in fascicles in the axils of the leaves, rarely in 
racemes. Perianth single, usually coloured, with the base of the tube 
adhering to the ovary, tubular, with the limb very irregular and 
oblique, entire or 2- or 3-cleft, or regular and 3-toothed; segments 
with valvate xstivation. Petals absent. Stamens definite, usually 
6 or 12, rarely 9; filaments very short and often adhering to the style; 
anthers 2-celled, longitudinally dehiscent. Ovary syncarpous, adhering 
to the bottom of the tube of the perianth, generally 6-celled, more 
rarely 3-celled, and very rarely 4-celled; ovules numerous, ascending 
or horizontal from the axis of the ovary, anatropous; style very short 
and thick; stigmas 6, radiating above the stamens. Fruit a capsule 
or berry loculicidally dehiscent, rarely indehiscent. Seeds numerous, 
with a membranaceous testa; albumen dense, fleshy or somewhat 
horny; embryo minute; cotyledons scarcely apparent until germi- 
nation; radicle inferior. 
GENUS T—ASARUM. Jinn. 
Perianth bellshaped, with the tube wholly adherent to the ovary, or 
suburceolate and adhering to the ovary only by its base; limb regular, 
3-cleft or 3-partite. Stamens 12, the filaments more or less distinct 
VOL. VII. N 
