322 ACANTHACEiE. 



and mainly tropical or subtropical order, one strongly marked tribe of which is 

 represented in ornamental cultivation by Thunhergia, another sparingly so by 

 the Acanthus of the Old World ; the others have several North American repre- 

 sentatives. 



Tkire I NELSONIEiE. Corolla imbricated in the bud ; upper lip exterior. Seeds 

 small and globular, attached by a small ventral papilliform funicle, without reti- 

 nacula, not umcilaginous when wetted: embryo in a thin layer of albumen ! (In 

 char, nearest to ScrophulariaceoR, but capsule and habit of AcanlhncecB.) 

 1 FLYTRARIA Calyx 4-parted; lower division sometimes 2-toothed. Corolla with 

 cvlindraceous tube, funnelform tliroat, and 5-lobed or somewliat bilabiate limb. Stamens 

 2 ■ filaments very short, inserted low in the throat : anther-cells equa and parallel. 

 Stiema 2-lobed. Ovules 6 to 10 in each cell. Capsule oblong, thinner and contracted at 

 basi acute at tip. Seeds globular. Bracts of the solitary or fasciculate-clustered spikes 

 and the similar scales of the scape imbricated, glumaceous. 

 Tribe II. Ruellie^. Corolla convolute (sinistrorsely) in the bud, either bilabiate 

 or nearly regular. Seeds flat, attached by the edge to retinacula. (Stamens in 

 ours didynamous, the long and the short filament on each side contiguous or united 

 at base by a membrane •, the anthers 2-celled, and the cells equal and parallel : 

 style with linear or subulate stigmatose apex, the posterior lobe wanting or reduced 

 to a minute tooth, or rarely 2 equal uarrow stigmas.) 



* Corolla deeply bilabiate : capsule terete and 2-celled to the very base. 



2 TTYGROPHIL A Calyx deeply and almost equally 5-clef t or parted. Corolla narrow ; 

 lies erect at base and above (at least the lower) spreading, 2- and 8-lobed. Anthers oblong, 

 muticous. Capsule oblong-linear, several-seeded. Flowers sessile in the axils. 



* * Corolla not obviously or only moderately bilabiate, the 5 lobes broad and roundish, 

 spreading : capsule with the base more or less contracted into a solid short stipe. 



3 CALOPHANES Calyx deeply 5-cleft or parted ; lobes elongated setaceous-acuminate 

 ' or aristiform Corolla funnelform, with ample limb, either somewhat manifestly bilabiate, 



or with 5 equal broad and spreading lobes, the two posterior a little higher united. An- 

 thers mucronate, or at least mucronulate, or sometimes aristate at base. Ovules a single 

 pair in each cell. Capsule oblong-linear, 2-4-seeded. . 



4 RUELLIA Calyx deeply 5-cleft or parted; lobes mostly linear or lanceolate. Corolla 

 ' with funnelform or campaniilate throat on a narrow and sometimes elongated tube ; the 



5 ovate or rounded lobes nearly similar and spreading, or the posterior rather more 

 united. Anthers muticous, oblong-sagittate. Ovules 3 to 10 in each cell. Capsule oblong- 

 linear or clavate, several- {G-20-) seeded. 

 Tribe III JUSTICIEiE. Corolla imbricated in the bud ; the posterior lobes or 

 lip interior. Seeds and capsule of the preceding tribe ; in the last two genera the 

 placentiferous half-portions separating below from the valve after dehiscence. 



* Stamens 4, in the throat of the corolla : filaments short : anthers one-celled, ovate-lan- 

 ceolate or oblong, muticous at base, their tips sometimes lightly cohering by a minute 

 beard: corolla with 5 plane obovate lobes, the two posterior usually united a li tie 

 higher : stigma naked, truncate or obscurely funnelform : ovules 2 in each cell : calyx 

 5-sepalous or 5-parted into narrow nearly equal divisions. 



5 STENANDRIUM Lobes of the salverform corolla all equally spreading. Low herbs. 



6 BERGINIA Posterior lobes of the corolla nearly erect, forming an upper lip, the 

 3 others larger and widely spreading. Anterior pair of filaments bearded on the mner 

 side: anthers ovate-lanceolate. Seeds (mostly 2) rugose. Fruticulose. 



* * Stamens 2 and no rudiments : anthers 2-celled: ovules 2 in each cell ; capsule usu- 

 ally more or less obcompressed, and with a conspicuous stipe-like solid base. 



^- Placentae not separating from the valves of the capsule. 



++ Anther-cells equ.al, parallel and contiguous, muticous: limb of corolla somewhat 



eauallv 4-narted : shrubby plants : bracts and bractlets small and narrow or minute : 



calyx small, 5-parted or 5-cleft ; the divisions narrow : stigma obscurely capitate or 



emarginate :' filaments filiform, inserted in the throat. 



7 PARLOV/RIGHTIA. Corolla with narrow tube shorter than the lobes ; throat not 



dilated; limb 4-parted down to the tube; lobes entire, oblong, nearly similar, widely 



