MONOPETALOUS EXOGENOUS PLANTS. 42? 



cons ; stems ascending, hranched ; leaves sessile, pinnatifid, 

 the segments obovate, abruptly acuminate ; pedicels short 

 or elongated; seimls linear-oblong, acute, two-thirds the 

 length of the pale-blue or white corolla ; stamens exserted. 

 Prairies. — Buckley. 



90. HYDROLEA FAMILY. Order, HYDROLEACEiE. 



Glandular-pubescent or bristly herhs, with entire alter- 

 nate leaves ; flowers regular, axillary and solitary or clus- 

 tered, or in terminal corym]3S or coiled bracted spikes; 

 calyx 5-parted ; corolla somewhat bell-shaped, 5-lobed, im- 

 bricated in the bud ; stamens 5, inserted on the tube of 

 the corolla, and alternate with its lobes, the filaments 

 oftener hairy ; styles 2, separate ; stigmas capitate ; ovules 

 numerous, anatropous ; capsule many-seeded, more or less 

 2-celled by the meeting of the two parietal placentae, 2 or 

 rarely 4 valved, opening through the middle of the cells, or 

 at their margins ; embryo straight, in fleshy albumen. 



HYDROLEA, L. 



Calyx 5-parted; corolla short, bell-shaped, 5-cleft, the 

 lobes spreading; stamens somewhat exserted, with the 

 filaments dilated at the base ; anthers sagittate ; styles 

 2 (rarely 3), separate; capsule globose, 2-celled, or im- 

 perfectly 4-celled by the introversion of the placentae, 

 2-valved. — Herbs, growing in water or muddy places, with 

 entire leaves, often with spines in their axils, and blue axil- 

 lary or corymho?>^ floioers. 



H. QUADRiVALVis, Walt. Spiny ; ste^n ascending from 

 a creeping base, hispid, mostly simple ; leaves lanceolate, 

 acute, pubescent on the veins, tapering into a petiole; 

 floivers axillary, the lower ones clustered, the upper soli- 

 tary, short-peduncled ; calyx-lobes linear, nearly as long as 

 the corolla; s^a??ie;z5 included ; cfl^j9S2<?e almost 4-celled, by 

 the introversion of the placentae, 2-valved. July and 



