ACANTHACEX. (ACANTHUS FAMILY.) 303 
2. DIPTERACANTHUS, Nees. 
Calyx 2-bracted, 5-parted, with linear or bristle-like lobes. Corolla funnel- 
shaped, 5-lobed ; the lobes equal, rounded. Stamens 4, didynamous, included : 
anthers sagittate. Style simple, or 2-cleft at the apex. Capsule narrowed 
below the middle, flattened contrary to the partition, 4—12-seeded. Seeds borne 
above the middle, supported by curved appendages of the placentz. — Perennial 
herbs, with tumid joints, entire opposite leaves, and axillary solitary or clustered 
nearly sessile flowers. Corolla white, blue, or purple. 
$ 1. Carormaxrs.— Anther-cells pointed at the base: style simple: capsule 
4-seeded. 
1. D. oblongifolius. Pubescent and somewhat hoary; stem 4-angled, 
erect from a creeping base, simple or sparingly branched ; leaves nearly sessile, 
oval or obovate, obtuse, the upper ones narrower and often acute ; flowers soli- 
tary or 2-3 in a cluster; calyx-lobes subulate-setaceous, as long as the oblong 
bracts, and tube of the spotted purple corolla. (Ruellia oblongifolia, Michx.) — 
Dry sandy pine barrens, Florida to South Carolina, and westward. June- 
August. — Stem 6/-12' high. Leaves }/-1! long. Corolla 1’ long, rather 
exceeding the leaves. 
2. D. riparius, n. sp. Stem minutely pubescent, erect from a creeping 
base, simple, slender ; leaves smooth, membranaceous, oblong, obtuse, slightly 
crenate, tapering into a long and slender petiole; flowers clustered, sessile ; 
calyx-lobes subulate-setaceous, shorter than the spatulate-oblong bracts ; corolla 
White, 3-4 times shorter than the leaves. — Shady banks of Little River, Middle 
Florida. June and July.— Stems 19-119 high. Leaves l'-1j!long. Co- 
rolla 3 long. 
3. D. humistratus. Stem smooth, diffuse, creeping; leaves oblong-oval, 
entire, narrowed into a petiole ; flowers nearly sessile, solitary or 2-3 in a clus- 
ter; bracts oblong-spatulate, shorter than the setaceous calyx-lobes ; capsule 
lanceolate, smooth. (Ruellia humistrata, Michr.) — Grassy places, Florida to 
South Carolina. — Plant small. Leaves y long. 
4. D. linearis, Torr. & Gray. Small, rough-pubescent ; stem prostrate, 
diffuse, very leafy ; leaves oblong-linear, entire, narrowed toward the base, ob- 
tuse; calyx-lobes setaceous, hairy; bracts similar to the leaves; capsule oblong, 
4angled, at length 4-valved, 2 — 4-seeded. — South Florida. — Stem. 6! long. 
ves 4 — 6" Jong. i 
$ 2. DrerEnACcAN THUS. — Anther-cells pointless : style 2-cleft at the apex : capsule 
i 8 — 12-seeded. pos 
5. D. ciliosus, Nees. Hirsute with white hairs; leaves oval or ovate- 
‘Oblong, nearly sessile ; flowers solitary or 2-3 in a cluster; tube of the corolla 
-twice as long as the setaceous calyx-lobes, and much longer than the short 
"annel-shaped throat; capsule smooth. (Ruellia ciliosa and R. hybrida, Pursh.) 
— Dry soil, Georgia, near Savannah, Pursh., and westward. July and Aug.— 
‘Stem varying from a few inches to 3° high. Leaves 1/-2! long. Corolla 2! - 
long, pale blue. ot o7 wk’ ‘ca 
