There is still much confusion regarding the distribution of this species and T. purpurascens. Collectors would confer a favor by gathering fruit as well as flowers. "This species is never glandular, so that all specimens with glandular pubescence are apparently referable to T. purpurascens."
(3057.) T. venulosum, Trelease, Proced. Bos. Soc. Nat. Hist., XXIII., 302.
"Glabrous and glaucous, the stem, petioles and sepals purple-tinted, the foliage typically pale or whitened. Stem simple, erect, 7-20 inches high. Stem leaves 2-3, long petioles, 3-4 ternate. Leaflets approximated, short stalked, moderately firm, rounded and lobedat the apex as in T. dioicum, the lower surface rugose-veiny. Panicle simple, narrow, its short erect branches few-flowered. Flowers dioecious, small. Sepals ovate. Stamens 10-20, on slender filaments; anthers oblong, slender-pointed. Achenia about eight, nearly sessile, 4 mm. long, ovoid tapering into a straight beak; thick-walled and otherwise similar to those of T. dioicum except that they are two-edged and commonly with one less groove on each side. Stigma sagittate. Seed ovid, pointed at one end, 1X2 mm., filling the ovary." British America. (Franklin Expedition.) Saskatchewan region. (Bourgeau.) On the Nechacco River, Northern British Columbia, 1875. (Macoun.)