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..
An erect biennial, brittle, branching herb, with alternate deeply pinnatifid leaves, yellow-sap and yellow flowers in umbels. Sepals 2. Petals 4. Stamens 00. Placentae 2. Style short, distinct; stigma not dilated, 2-lobed. Capsule linear, upwardly dehiscent from the base. Seeds smooth, shining, crested. [Name Greek for the swallow, which appears at about its flowering time.] A monotypic genus of temperate Europe and Asia.
Chelidonium majus L. Sp. Pl. 505. 1753.
Weak, 1°-2° high, sparingly pubescent. Leaves thin, 4'-8' long, glaucous beneath, 1-2-pinnatifid, the segments ovate or obovate, crenate or lobed; petioles often dilated at the base; flowers 6"-8" broad, in axillary pedunculate umbels; petals rounded; pedicels slender, 2"-6" long, elongating in fruit; capsule glabrous, 1'-2' long, tipped with the persistent style and stigma.
Waste places, roadsides and even in woods, Maine to Ontario, Pennsylvania, and North Carolina. Naturalized or adventive from Europe. Summer. Called also greater Celandine, to distinguish it from Ficaria, the small or lesser celandine. Swallow-wort. Tetterwort. Killwort. Wart-wort. April-Sept.