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, dark green, often minutely pubescent. Stem rather stout, erect, 1 1/2°-5° tall, fleshy, topped by a 5-8-rayed umbel, branched above, the branches simple or forked; the leaves oblong or oblanceolate, 1 /2'-4' long, mostly obtuse at the apex, sessile, often undulate, more or less pubescent beneath, those of the stem scattered, those subtending the umbels verticillate; bracts opposite, ovate or nearly reniform; involucres cam-panulate, nearly 2" long, bearing 5 reniform crenulate unappendaged glands; capsule depressed-globose, minutely warty; seeds ovoid-globose.
Euphorbia Peplus L. Sp. Pl. 456. 1753. Tithymalus Peplus Hill, Hort. Kew. 172/3. 1768.
Annual, glabrous. Stem rather slender, erect or nearly so, 4'-12' high, simple or branched, topped by a 3-5-rayed umbel; stem-leaves scattered, oblong or obovate, 1/2' - 1 1/4' long, obtuse or retuse, entire, crisped, narrowed into a slender petiole; those at the base of the umbel whorled; bracts opposite, ovate or triangular-ovate, apiculate, sessile; involucres campanulate, almost sessile, less than 1" long, bearing 4 crescent-shaped unap-pendaged glands prolonged into slender horns; capsule globose-ovoid, 1"-1 1/2" in diameter, slightly nodding, smooth, the lobes 2-keeled; seeds oblong or oblong-ovoid, whitish, nearly terete, marked with 1-4 series of pits.
In waste places, New Brunswick to western New York, Wisconsin, Iowa, New Jersey, Pennsylvania and West Virginia. Bermuda, Jamaica. Adventive from Europe. Devil's-milk. Seven sisters. Wartweed. June-Sept.
1859: 82. Euphorbia ohiotica Steud. & Hochst.; Boiss. in DC.
Prodr. 15: Part 2, 142. 1862.
Biennial, yellowish green, often tinged with red, glabrous. Stem slender, usually decumbent at the base, 4'-15' long, branched, topped by a 3-rayed umbel; branches forked or umbellately branched; leaves, except the whorl at the base of the umbel, scattered, spatulate to ovate, ą-\Y long, obtuse or mucronulate, entire, flat, narrowed into a slender petiole; bracts opposite, ovate-reniform; involucres campanulate, 1 1/4" long, sessile, bearing 3 or 4 crescent-shaped unappendaged glands prolonged into slender horns; capsule globose-ovoid, 1 1/2" in diameter, glabrous, the lobes rounded; seeds oblong, terete, irregularly pitted.
Tithymalus falcÓtus (L.) Kl. & Garcke, a native of Europe, with spatulate leaves, subulate-tipped bracts and rugose-pitted seeds, has been found in western Virginia.