ACANTHACEA2. (ACANTHUS FAMILY.) 293 
DIANTHEBA, Gronov. Dianthera. 
Calyx 5-parted. Corolla deeply 2-lipped ; the upper lip erect, 
notched; the lower spreading, 3-parted. Stamens 2 : anthers 2- 
celled, the cells placed one lower down than the other. Pod ob- 
ovate, compressed, contracted at the base into a short stalk, 4- 
seeded. — Perennial herbs, growing in water, with narrow and 
entire leaves, and purplish flowers in axillary peduncled spikes or 
heads. (Name from 81 y, double, and avdypa, , anther , the separated 
cells giving the appearance of two anthers on each filament.) 
1- I>. Americana, L. (Willow-leaved Dianthera.) 
Leaves linear-lanceolate, elongated; spikes oblong, dense, long-pe- 
duncied. (Justfcia pedunculdsa, Michx.) — Borders of streams and 
ponds, N. W. Vermont and along the Great Lakes and their tributa¬ 
ries to Ohio and Wisconsin. July. 
2, DIPTER ACANTHUS, Nees. (Ru^llia partly, L.) 
Calyx deeply 5-cleft. Corolla funnel-form, the spreading ample 
limb almost equally and regularly 5-cleft. Stamens 4, included, 
didynamous : cells of the somewhat arrow-shaped anthers parallel 
and nearly equal. Pod somewhat compressed, and stalked at the 
base, 8-12-seeded. Seeds with a mucilaginous coating.—Per¬ 
ennial herbs, not aquatic, with ovate or elliptical nearly entire 
leaves, leafy bracts, and clustered blue or purple flowers. (“Name 
from dtirrepos, two-winged , and anavOos, the Acanthus ; on account 
of the 2-leaved peduncles.’’) 
* Corolla large and conspicuous . 
1. I>. Strepens, Nees. Somewhat smooth; leaves ovate or 
ovate-oblong; peduncles axillary, very short; calyx-lobes lanceolate , 
acute, ciliate , spreading, shorter than the tube of the elongated funnel- 
form corolla. (Ruellia strepens, L. partly.)—Rich soil, from Penn, 
and Ohio westward and southward. July-Sept. — Plant l°-2° 
high : corolla 2' long. Primary bracts ovate. 
2. R. liybridllS, Nees. More or less hairy; leaves oval or 
oblong; peduncles axillary, very short; calyx-lobes slender thread- 
form from a linear-lanceolate base, hairy , scarcely shorter than the 
tube of the elongated funnel-form corolla, equalling the linear or lan¬ 
ceolate bracts. (R. hybrida, Pursh.) — Rich soil, Ohio and south¬ 
ward. 
* * Corolla small and inconspicuous , very deciduous. 
3- D* micrantllUS, Engelm. & Gray. Smoothish; leaves 
25* 
