This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Perennial herbs, with ternate or ternately compound leaves, or the basal ones sometimes undivided, and compound umbels of yellow or purple flowers. Involucre none, or of 1-3 bracts. Involucels of several small bracts. Calyx-teeth prominent, acute. Stylopodium none. Style slender. Fruit ovoid or oblong, glabrous or nearly so, scarcely flattened. Carpels somewhat dorsally flattened, the ribs or at least some of them strongly winged; oil-tubes solitary in the intervals, 2 on the commissural side. Seed-face flat. [Name indirectly from the island Thapsus.]
Only the following species, natives of eastern North America. Type species: Thaspium aureum Nutt.
Leaves mostly ternate; segments crenate, thickish.
Leaves mostly biternate; segments incised or lobed, rather thin.
Segments ovate, incised.
Segments pinnatifid into oblong lobes.
Thapsia trifoliata L. Sp. Pl. 262. 1753.
Smyrnium atropurpureum Desr. in Lam. Encycl. 3: 667.
1789. Thaspium aureum Nutt. Gen. 1 196. 1818. Thaspium atropurpureum Nutt. Gen. 1: 196. 1818. T. trifoliatum Britton, Mem. Torr. Club 5: 240. 1894. Thaspium trifoliatum aureum Britton, Mem. Torr. Club 5: 240. 1894.
Glabrous throughout; stems erect, more or less branched, I°-2° high. Upper stem-leaves short-peti-oled, ternate, or rarely biternate, the segments ovate or ovate-lanceolate, 1-2' long, crenate-dentate all around; basal leaves long-petioled, sometimes undivided; umbels 1'-2' broad; petals dark purple or yellow; fruit 2" long, all the ribs usually winged.
In woods, Rhode Island to Georgia, Tennessee, Illinois, Missouri, Arkansas and Wyoming. Purple alexanders. Round-heart. The purple-flowered and yellow-flowered races are, apparently, otherwise indistinguishable. June-July.
Smyrnium barbinode Michx. Fl. Bor. Am. 1:
167. 1803. Thaspium barbinode Nutt. Gen. 1: 196. 1818. T. barbinode angustifolium Coult. & Rose, Bot.
Gaz. 12: 137. 1887.
Erect, divergently branched, 2°-4° high, pubescent at the joints and sometimes also on the young shoots and rays of the umbels. Leaves more or less petioled, mostly bipin-nate (the upper often simply pinnate and the basal 3-pinnate); segments ovate to lanceolate, acute at both ends, or rounded at the base, rather thin, incised-serrate or cleft, 1'-2' long; umbels l'-2' broad; flowers light yellow; fruit nearly 3" long, 7 of the ribs commonly broadly winged.
Along streams, Ontario to Minnesota, Kansas, Florida, Kentucky and Arkansas. May-June.
Divergently branched, 2°-4° high, more pubescent than the preceding species. Leaves distant, ternately pinnatifid into numerous oblong or linear-oblong lobes, the basal ones long-petioled and very large; flowers light yellow; fruit 1 1/2"-2 1/2" long, puberulent, all the ribs winged, but 7 of the wings broader than the other 3.
In woods and copses, Kentucky to North Carolina and Tennessee. June.