240 ACANTHUS FAMILT. 



§ 1. Twining tropical herbs {or rult. ns herbs), with nearly reguhtr b-hhed corolla, 

 and globular seeds suijporled by a cartilagimms ring or sliallow cup. 



1. THUNBERGIA. Flowers enclosed when in bud by a pair of large leaf-like 



braotlets borne below the short cup-shaped calyx. CuroUa with a mostly 

 somewhat curved tube and an abruptly wide-spreading border of 5 rounded 

 equal lobes, convolute in the bud. Stamens 4, included. Pod globular, 

 tipped with a long and conspicuous flattened beak, 2^4-seeded. Peduncles 

 axdiary, 1-flowered. 



§ 2. Erect or spreading : all the following are herbs, with fiat seeds borne on hook- 

 like processes {reiinacula) : calyx 4 -~5-parted, mosily 2'bracted. 



2. ACANTHUS. Corolla of one 3-lobed lip, the upper lip wanting. Stamens 4, 



with one-celled ciliate anthers. Leaves pinnatifld. Klowers in a spike. 



3. RUELLIA. Corolla funnel-form, with an almost equally 5-lobed spreading 



border, convolute in the bud. Stamens 4, included : cells of the anthers 

 parallel. Pod nan'ow, contracted into a stalk-like base, above 4 - 12-seeded. 



4. DICUPTERA. Corolla 2-lipped, the lower lip 3-lobed, the upper 2-cleft or 



entire ; but the flower as it were reversed so that the 3-lobed lip seems to- be 

 the upper one. Stamens 2, protruded: cells of the anther equal, but one 

 placed below the other. Pod 2 - 4-seeded below the middle. 

 6. DIANTHERA. Corolla 2-lipped, the upper lip erect ai^d notched; the lower 

 3-lobed, wrinkled or veiny to\Vards the base, spreading. Stamens 2 : cells of 

 the anther one below the other, mostly unequal. Pad-, flattened above, con- 

 tracted into a stalk-like base, 4-seeded above the middle. 



1. THUIfBEEGIA. (Named from the Swedish botanist Thunberg.) 

 Showy flowers produced all summer. 



T. al^ta (so named from its winged petioles) from Africa, is the one com- 

 monly cultivated (as an annual) in many varieties as to size and color of flower, 

 buff, orange, white, &c., usually with blackish-purple eye; herbage soft-downy 

 or hairy ; leaves between heart-shaped and arrow-shaped. 2^ 



2. ACANTHUS. (Old Greek and Latin name, from the word for sptnc or 



prickle. ) y. 



A. mollis, one of the classical species, from S. Eu., is occasionally cult., not 

 hai-dy N. : the broad sinuately and deeply pinnatifid leaves mostly from the root, 

 hardly at all prickly ; flowers on a short scape, dull-colored. 



3. EXTELLIA. (Named for the herbalist Ruelle.) Onrs are wild herbs, 

 chiefly southern, with purple or blue showy flowers, mostly in clusters, 

 produced all summer. "J/ 



§ 1 . Cells of the anther pointed at base : stigma only one : pod i-serded. 

 R. oblongifolia. Pine barrens S. : downy, 6'- 12' high from a creefiing 

 base, with nearly sessile oval leaves barely 1' long, almost bristle-shaped sepals, 

 but oblong bracts, and spotted pui-ple corolla 1' long. 



§2. Cells of the anther blunt: stigmas 2 : pod S-l2-speded: stems \°-i° hgh. 



R. cilibsa. Dry soil W. & S. . clothed with soft white hairs, the oval or 

 oblong leaves nearly sessile, pale blue corolla (about 2' long) with slender tube 

 much lon,'£er than the inflated upper part and than the bristle-shapedsepals. 



R. Strepens. Richer soil, from Penn. AV. & ,S. : smooth or slightly down/, 

 with ohovate or oblong leaves (V-i' long) narrowed into a petiole, and pnrple- 

 blue corolla (l'-2' long) with tube hardly longer than the expanded portion or 

 than the linear-lanceolate sepals, 



4. DICLIPTEBA. (Greek words for donlJe, shut, from the 2-valvcd pod.) 

 D. braohiita, of low banks S. is nearly smooth, with 6-angled stem bear- 

 ing many branches, thin ovate-oblong iiointed leaves on slender petiole, and 

 inten-uptcd spike-like clusters of small purple flowers, each with a nair of con- 

 spicuous flat bracts. 2/ 



