322 ACAXTHACEiE. 



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. 



TiJiBE I. NELSONIEJD. Corolla imbricated in the bud ; upper lip exterior. Seeds 

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

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

 char, nearest to Scwphidnriacece, but capsule and habit of Acanlhncecc.) 



1. ELYTRARIA. Calyx 4-pai-ted ; lower division sometimes 2-toothed. Corolla with 

 cyliiulraceous tube, funnclform throat, and 5-lobed or somewliat bilabiate limb. Stamens 

 2 : tilanients very short, inserted low in the throat : anther-cells equal and parallel. 

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

 base, 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 (siuistrorsely) in the bud, either bilabiate 

 or neai'ly regular. Seeds flat, attached by the edge to retinacula. (Stamens in 

 ours didynanious, 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 narrow stigmas.) 



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



2. HYGROPHILA. Calyx deeply and almost equally 5-cleft or parted. Corolla narrow ; 

 lips erect at base and above (at least tlie lower) spreading, 2- and .>lobcd. 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 roimdish, 

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



3. CALOPHANES. Calyx deeply 5-cleft or i)arted ; lobes elongated setaceous-acuminate 

 or aristiform. Corolla funnelform, witli ample limb, either somewliat manifestly bilabiate, 

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

 thers mucronatc, 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 campanulate 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. JUSTICIE.E. 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 little 

 liigher: 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 salvcrform corolla all equally siireading. Low herbs. 



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

 3 otliers larger and widely spreading. Anterior pair of filaments bearded on the inner 

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



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

 ally more or less obcomi)rcsscd, and with a conspicuous stipc-likc solid base. 



H— Placenta? not separating from the valves of the capsule. 

 +->• Anther-cells equal, parallel and contiguous, muticous : limb of corolla somewhat 

 equally 4-parted : shrubby i)lants : 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. CARLOWRIGHTIA. Corolla with narrow tube shorter than the lobes; throat not 

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



