240 



ACANTHACEAE. 



VOL. III. 



or 2 only ; anthers mostly 2-celled, the sacs longitudinally dehiscent. Disk annular 

 or cup-like. Ovary 2-celled; ovules 2-10 in each cavity, anatropous or amphitro- 

 pous; style filiform, simple; stigmas I or 2. Capsule dry, 2-celled, loculicidally 

 elastically 2-valved. Seeds globose or orbicular, not winged, borne on curved pro- 

 jections (retinacula) from the placentae, the testa close, mostly roughened, often 

 developing spiral threads and mucilage when wetted. Endosperm in the following 

 genera none ; cotyledons flat, commonly cordate. 



About 175 genera and 2000 species, natives of temperate and tropical regions of the Old World 

 and the New. 

 Corolla convolute in the bud, nearly regular ; stamens 4. 



Ovules 2 in each cavity; capsule 2-4-seeded. i. Dyschoriste. 



Ovules 3-10 in each cavity; capsule 6-2o-seeded. 2. Ruellia. 



Corolla imbricated in the bud, strongly 2-lipped ; stamens 2. 



Lower lip of the corolla 3-cleft ; flowers bracted, not involucrate. 3. Dianthera. 



Lower lip of the corolla entire or 3-toothed ; flowers involucrate. 4. Diapedium. 



i. DYSCHORISTE Nees, in Wall. PI. As. Rar. 3: 81. 1832. 

 [CALOPHANES Don; Sweet, Brit. Fl. Card. (II). pi. 181. 1833.] 



Erect or procumbent perennial herbs or shrubs, with entire leaves (smaller ones some- 

 tibes fascicled in their axils), and blue or purple, rather large, bracted flowers, axillary, 

 solitary or clustered. Calyx deeply 5-cleft, the lobes setaceous. Corolla funnelform, the 

 tube slightly curved, enlarged above, or cylindraceous, the limb spreading, 5-lobed, somewhat 

 2-lipped, the lobes rounded, simstrorsely convolute in the bud. Stamens 4, didynamous, 

 included, all anther-bearing in our species ; anther-sacs mucronate at the base. Ovules 2 in 

 each cell of the ovary ; summit of the style recurved ; stigma simple, or of 2 unequal lobes. 

 Capsule oblong, linear, narrowed at the base, 2-4-seeded, in some species coherent. Seeds flat, 

 orbicular, attached by their edges to the retinacula. [Greek, referring to the coherent capsule- 

 valves.] 



About 30 species, of wide distribution in warm and tropical regions. Besides the following, 

 4 others occur in the southern and southwestern United States. Type species : Dyschoriste 



depressa Nees. 



i. Dyschoriste oblongifolia (Michx.) 

 Kuntze. Dyschoriste. Fig. 3888. 



Ruellia biflora L. Sp. PI. 633. 1753? 



R. oblongifolia Michx. Fl. Bor. Am. 2: 23. 1803. 



Calophanes oblongifolia Don ; Sweet, Brit. Fl. 



Card. (II.) pi. 181. 1833. 

 Dipteracanthus biflorus Nees, Linnaea 16 : 294. 



1842. 

 D. oblongifolia Kuntze, Rev. Gen. PI. 486. 1891. 



Rootstocks horizontal, slender ; stems slen- 

 der, erect, simple, or branched below, pubes- 

 cent or puberulent, obtusely 4-angled, 6'-i5' 

 high, rather stiff. Leaves ascending or erect, 

 oblong or oval, rounded at the apex, somewhat 

 narrowed at the base, very short-petioled, or 

 sessile, pubescent or glabrate, 8" -15" long; 

 flowers commonly solitary in the axils; calyx- 

 segments filiform, hirsute, exceeding the ob- 

 long, obtuse bractlets ; corolla blue, or mottled 

 with purple, 8"-i2" long, slightly 2-lipped, its 

 tube enlarged above; capsule oblong, about 

 one-half the length of the calyx; anther-sacs 

 mucronate-aristate at the base. 



In sandy pine barrens, Virginia to Florida, 

 mainly near the coast. June-Sept. 



2. RUELLIA [Plumier] L. Sp. PI. 634. 1753. 



Perennial herbs, or shrubs, mostly pubescent, with entire or rarely dentate leaves, and 

 large violet blue white or yellow flowers, solitary or clustered in the axils, or cymose in 

 terminal panicles, or sometimes cleistogamous and inconspicuous. Calyx 5-cleft, or 5-parted, 

 the segments narrow. Corolla funnelform or salverform, the tube usually narrow, slightly 

 enlarged above, the limb spreading, 5-lobed, the lobes obtuse, mostly nearly equal, sinistrorsely 

 convolute in the bud. Stamens 4, included or exserted ; anther-sacs not mucronate at the 

 base. Ovules 3-10 in each cavity of the ovary; apex of the style recurved; stigma simple, or 

 of 2 unequal lobes. Capsule oblong or club-shaped, compressed or terete, 6-20-seeded. Seeds 

 compressed, ovate or orbicular, attached by their edges to the retinacula. [Named for I. 

 Ruel or de la Ruelle, 1474-1537, an early French herbalist.] 



