444 FLORA OF TEXAS. 



B. TEXELLA. Stem 6-12' high, branched ; branches 

 alternate, opposite or alternate, many-flowered ; calyx-\ohQ^ 

 subulate, as long as the tube of the greenish-white corolla; 

 lobes of the corolla erect, acute ; anthers globose ; capsule 

 oblong-lanceolate ; leaves alternate or opposite. 



OBOLARIA, L. 



Low sparingly-branched perennial herb, with opposite 

 wedge-obovate leaves, and single or clustered axillary and 

 terminal purplish-flowers ; calyx of 2 spatulate bract-like 

 sepals ; corolla bell-formed, 4-cleft, imbricated in the bud ; 

 stamens 4; anthers round-cordate; style short; stigma 

 2-lipped; capsule ovoid, 1-celled; seeds numerous, cover- 

 ing the base. 



O. ViRGii^iCA, L. Plant smooth, purplish, 3-8' high ; 

 branches generally 3-flowered. 



LIMNANTHEMUM, Gmel. 



Perennial aquatic herbs, with floating circular or cor- 

 date spongy leaves, and white peduncled floivers clustered 

 near the summit of the long petiole ; calyx S-pai-ted ; 

 corolla wheel-shaped, 5-parted, the lobes infolded in the 

 bud, ciliate, and glandular-crested at the base ; stamens 5 ; 

 style short or none; stigma 2-lobed, persistent; capsule 

 1-celled, opening irregularly ; seeds few or many ; testa 

 w^oody. 



L. TRACHYSPERMUM^, Gray. Leaves (3'-5' wide) circu- 

 lar, crenate, rough and pitted beneath ; petioles stout, 

 dotted, elongated ; seeds glandular roughened. Ponds in 

 deep water. April- June. 



95. DOGBANE FAMILY. Order, Apocynace^. 



Herbs or shrubs, with acrid milky juice, mostly opposite 

 entire exstipulate leaves, and regular cymose or panicled 



