This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", 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..
Slender or filiform erect glabrous annual or biennial herbs, the leaves reduced to minute opposite subulate scales, or some of them alternate, and white purplish or yellowish racemose or paniculate flowers, or these rarely solitary and terminal. Calyx deeply 4-parted, the segments lanceolate, acuminate, keeled. Corolla campanulate, deeply 4-cleft, the lobes imbricated in the bud. Stamens 4, inserted at the sinuses of corolla; filaments slender, longer than the ovate sagittate anthers. Ovary 1-celled, the placentae intruded; ovules numerous; style very short or none; stigma 2-lobed. Capsule ovoid-oblong, compressed, acute, 2-valved. Seeds minute, covering the whole inner surface of the capsule. [In honor of Professor Benjamin Smith Barton, 1766-1815, of Philadelphia.]
Four species, natives of eastern North America. Type species: Bartonia tenella Willd.
Corolla yellowish, 1 1/2"-2" long.
Corolla-lobes oblong, abruptly tipped, erose.
1. B. virginica.
Corolla-lobes lanceolate, acute or acuminate, entire.
2, B. paniculata.
Corolla white, 3"- 4" long, its lobes spatulate.
3. B. verna.
Sagina virginica L. Sp. Pl. 128. 1753.
B. tenella Willd. Neue Schrift. Ges. Nat. Fr. Berlin 3: 445. 1801.
Bartonia virginica B.S.P. Prel. Cat. N. Y. 36. 1888.
Stem rather stiff, almost filiform, 4'-15' high, simple, or with few erect branches above, 5-angled, yellowish green, sometimes twisted. Subulate scales 1"-2" long, appressed, mostly opposite, the basal pairs close together, the upper distant; flowers mostly opposite; pedicels ascending or erect. 2"-6" long; corolla greenish yellow or whitish, 1 1/2"-2" long, its lobes oblong, obtuse, denticulate or erose. somewhat exceeding the calyx; stamens included; ovary 4-sided; stigma about ¥' long; capsule about 1 1/2" long.
In moist soil. Nova Scotia to Florida, Michigan, Minnesota and Louisiana. Screw-stem. July-Sept.
Centaurella paniculata Michx. Fl. Bor. Am. 1: 98.
1803. ?C. Moseri Steud. & Hochst.; Griseb. Gent. 308. 1839 B. paniculata Robinson, Rhodora 10: 35. 1908. B. lanceolata Small, Fl. SE. U. S. 932. 1903.
Slender,8'-16' high, mostly paniculately branched above, the branches and scales mainly alternate, the slender pedicels spreading or ascending. Corolla yellowish-white or greenish, about twice as long as the calyx, its lanceolate acute or acuminate lobes 1"-1 1/2" long; anthers yellow.
In wet soil, Massachusetts to Florida, Arkansas and Louisiana. Aug.-Oct.
Centaurella verna Michx. Fl. Bor. Am. 1: 97. pl. 12. f. 1. 1803. Bartonia verna Muhl. Cat. 16. 1813.
Stem thicker and less rigid than that of the two preceding species, usually simple, 2'-15' high, racemosely or corymbosely I-several-flowered. Bracts distant, appressed, some of them commonly alternate; flowers solitary at the ends of the elongated erect peduncles, 3 "-4" long; peduncles sometimes 2' long; corolla white, its lobes spatulate or obovate, obtuse, denticulate or entire, about 3 times the length of the calyx; ovary compressed; capsule about 21/2" high.
In moist sand, southern Virginia to Florida and Louisiana.