RHINANTHACEAE 1069 



22. HEMIANTHUS Xutt. 



Annual or perennial diminutive herbs:, with creeping stems. Leaves opposite : blades 

 manifestly longer than broad, indistinctly nerved. Flowers inconspicuous, solitary in the 

 axils. Calyx of 4 mostly united sepals. Corolla purple or whitish, very irregular, the 

 upper lip obsolete and the tube there cleft, the lower lip relatively large, with a long in- 

 curved middle lobe. Stamens 2 : filaments with long basal appendages : anther-sacs divari- 

 cate. Style-tips slender, each with 2 subulate stigmas. Capsule subglobose, many-seeded. 



1. Hemianthus micranthemoides Nutt. Stems often matted, glabrous, 2-8 cm. 

 long, with erect or ascending tips. Leaf-blades spatulate to obovate or oblong, 1-6 mm. 

 long : pedicels about as long as the calyx or becoming longer : calyx about 1 mm. long, 

 with oblong lobes : corolla often 2 mm. or sometimes 2.5 mm. long, the upper lip obsolete, 

 the lower lip with a linear incurved middle lobe and 2 shorter lateral lobes : each filament 

 with a basal appendage similar to itself : capsules subglobose, about 1 mm. in diameter. 



On muddy banks, New Jersey to Florida. Summer and fall. 



23. MICRANTHEMUM Michx. 



Annual or perennial diminutive herbs, with difiuse or creeping stems. Leaves oppo- 

 site : blades entii-e, commonly suborbicular, manifestly nerved, sessile. Flowers incon- 

 spicuous, solitary in the axils. Sepals 4, united at the base. Corolla white or purplish, 

 obscurely 2-lipped, the upper lip entire, this and the 3 lobes of the lower lip nearly equal, 

 or the middle lobe of the lower lip slightly larger, the corolla thus appearing more or less 

 equally 4-lobed. Stamens 2 : filaments dilated at the base : anther-sacs parallel. Style- 

 tips club-shaped or capitate. Capsule subglobose, many-seeded. 



1. Micranthemum orbiculatum ]\Iichx. Stems glabrous, 1-4 dm. long, sometimes 

 densely tufted and erect at the ends. Leaf-blades suborbicular, 5-10 mm. in diameter, 

 rounded or retuse at the apex : pedicels shorter than the calj'x : calyx-lobes 1 mm. becom- 

 ing 1.5 mm. long, narrowly oblong: corolla about 1-1.5 mm. broad, the lobes oblong: 

 capsules subglobose, 1-1.5 mm. in diameter. 



On muddy banks and in swamps and streams, North Carolina to Florida and Texas. Spring to fall. 



24. AMPHIANTHUS Torr. 



Annual or biennial amphibious glabrous herbs, with very short stems. Leaves mainly 

 basal : blades narrow, entire, sessile. Flowers variously disposed, some sessile or nearly 

 sessile on the short stem, others terminating elongated slender peduncles. Calyx of 5 

 unequal slightly united sepals. Corolla white, slightly 2-lipped, the upper lip and the 

 lobes of the lower lip short, rather square, retuse or notched. Stamens 2, included : fila- 

 ments adnate to about the middle of the corolla-tube : anther-sacs distinct. Stigma 2" 

 lobed. Capsule flattened, loculicidally dehiscent. Seeds narrow, regularly pitted. 



1. Amphianthus pusfllus Torr. Stems clustered, usually less than 1 cm. long. 



Leaves basal ; blades linear, 5-10 mm. long, blunt : flowers clustered on tiie short stem or 



those surmounting the filiform peduncles which vary in length with the depth of the water, 



solitary, subtended by a pair of oblong oval or ovate bracts, 3-8 mm. long : calyx-lobes 



oblong or nearly so : corolla white, 6-8 mm. long; tube funnelforra : capsules 2-2.5 mm. 



in diameter, 2-lobed. 



In water filling depressions in granite rocks, Georgia. Flowering and fruiting whenever there is 

 sufficient water present. 



25. CAPRARIA L. 



Perennial caulescent herbs or shrubby plants. Leaves alternate : blades longer than 

 broad, toothed. Flowers on axillary pedicels. Calyx of 5 narrow, almost equal sepals. 

 Corolla white, campanulate, with 5 flat lobes. Stamens usually 4 : anther-sacs 2, di- 

 vergent, confluent. Stigmas dilated or 2-lobed. Capsule short, 2-grooved, loculicidally 

 dehiscent. Seeds reticulated. 



1. Capraria biflora L. Stems 3-9 dm. tall, branching, sometimes pubescent. Leaf- 

 blades oblanceolate, cuneate or oblong, 1-4 cm. long, acute, sharply serrate above the 

 middle : pedicels solitary or 2 together, shorter than the subtending bracts : sepals linear- 



