240 ACAXTHUS FAMILY. 



§ 1. Twining tropical herbs (or cult, as herbs), with nearly regular h-ldbed corolla, 

 and globular seeds supported by a cartilaginous ring or shallow cup. 



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



bractlets borne below the short cup-shaped calyx. Corolla 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 

 axillary, 1-flowered. 



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

 like processes (retinacula) : calyx ^~b-parted, mostly 2-bracted. 



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



with one-celled ciliate anthers. Leaves pinnatifid. Flowers 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 narrow, contracted into a stalk-like base, above 4 - 12-seeded. 



4. DICLIPTERA. 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, 

 f. DIANTHERA. Corolla 2-lipped, the upper lip erect and notched; the lower 

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

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

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



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

 Showy flowers produced all summer. 



T. alkta (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, y. 



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



prickle. ) y. 



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

 hardy N. : the broad sinuately and deeply pinnatifid leaves mostly from the root, 

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



3. RUELLIA. (Named for the herbalist Ruelle.) Ours are wild herbs, 



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

 produced all summer, y. 



§ 1 . Cells of the anther pointed at base : stigma onhj one : pod '^-seeded. 



R. Oblongifolia. Pine barrens S. : downy, 6'- 12' high from a creeping 

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

 but oblong bracts, and spotted purple corolla 1 ' long. 



§ 2. Cells of the anther blunt: stigmas 2 : pod 8-l2-seeded: stems l°-4° high. 



R. Cili6sa. 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 longer than the inflated upper part and than the bristle-shaped sepals. 



R. Str6pens. Richer soil, from Penn. W. & S. : smooth or slightly downy, 

 with obovate or oblong leaves (l'-4' long) narrowed into a petiole, and purple- 

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

 than the linear-lanceolate sepals. 



4. DICLIPTERA. (Greek words for doiMe, shut, from the 2-valved pod.) 

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

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

 intciTupted spike-like clusters of small purple flowers, each with a pair of con- 

 spicuous flat bracts, y. 



