i6 



GENTIANACEAE. 



VOL. III. 



ments slightly longer than the ovate sagittate anthers. Ovary i-celled, with 4 internal 

 placental projections; ovules numerous; style distinct; stigma 2-lamellate. Capsule ovoid, 

 2-valved or irregularly bursting. Seeds minute, covering the whole interior of the capsule. 

 [Greek, obolus, a coin, alluding to the thick round leaves.] 



A monotypic genus of eastern North America. 



i. Obolaria virginica L. Pennywort. Fig. 3366. 



Obolaria virginica L. Sp. PI. 632. 1753. 



Stems 3'-6' high from a perennial base with thick fibrous 

 roots, bearing 2-6 pairs of thick small obtuse scales in 

 place of leaves. Floral leaves broadly obovate-cuneate, 

 obtuse, purplish, 4"-6" long; flowers sessile or nearly so 

 in the axils, in clusters of 1-4 (usually 3), and terminal; 

 corolla about 5" long, cleft to about the middle, the lobes 

 oblong, obtuse, entire, or denticulate; stamens included; 

 capsule 2i" long. 



In rich woods and thickets, New Jersey to Georgia, west to 

 Illinois and Texas. Ascends to 2600 ft. in Virginia. April-May. 



10. BARTONIA Muhl. ; Willd. Neue Schrift. Ges. Nat. Fr. Berlin 3 : 444. 1801. 



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 seg- 

 ments 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 i-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, \y 2 "-2" long. 



Corolla-lobes oblong, abruptly tipped, erose. i. B. virginica. 



Corolla-lobes lanceolate, acute or acuminate, entire. 2. B. pamculata. 



Corolla white, 3"-4" long, its lobes spatulate. 3- B. verna. 



i. Bartonia virginica (L.) B.S.P. 

 Fig. 



Yellow Bartonia. 



Sagina virginica L. Sp. PI. 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'-iS' high, simple, or 

 with few erect branches above, 5-angled, yellowish green, 

 sometimes twisted. Subulate scales i"-2" long, appressed, 

 mostly opposite, the basal pairs close together, the upper dis- 

 tant; flowers mostly opposite; pedicels ascending or erect, 

 2"-6" long; corolla greenish yellow or whitish, ii"-2" long, 

 its lobes oblong, obtuse, denticulate or erose. somewhat ex- 

 ceeding the calyx; stamens included; ovary 4-sided; stigma 

 about \" long; capsule about \\" long. 



In moist soil, Nova Scotia to Florida, Michigan, Minnesota and 

 Louisiana. Screw-stem. July-Sept. 



