RHINANTHACEAE 1069 
22. HEMIANTHUS Nutt. 
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 diffuse or creeping stems. Leaves oppo- 
site: blades entire, 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 Michx. 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 calyx : 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 pusillus Torr. Stems clustered, usually less than 1 cm. long. 
Leaves basal; blades linear, 5-10 mm. long, blunt: flowers clustered on the 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 funnelform: capsules 2-2.5 mm. 
in diameter, 2-lobed. 
In water filling depressions in graníte 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 bifldra 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- 
