WATERLEAF FAMILY 487 



at the apex to divided nearly to the base. Mature capsule unilocular or nearly bilocular 

 by the intrusion of the placentae, oblong to globose, loculicidally dehiscent. Ovules 2 to 

 very numerous on the 2 prominent, linear placentae, laterally attached. Seeds oblong to 

 orbicular, terete, angled, or flattened, foveolate or reticulate, or transversely corrugated, 

 or excavated on each side of a salient ridge. [Name Greek, meaning cluster.] 



A polymorphic American genus of perhaps 150-200 species, principally in the western United States and 

 Mexico, but with a few species in the eastern United States and South America. Type species, Hydrophyllum 

 tnagellanicum Lam. 



Seeds not transversely corrugated, or if so the ventral surface of the seed excavated on each side of a salient ridge, 

 and ovules only 2 to each placenta. 

 Corolla-scales a pair attached to the corolla-tube at the base of each filament, occasionally obsolete. 

 Seeds terete or angled and usually foveolate or reticulate, but not excavated. 



Leaves pinnately toothed or lobed or pinnatifid, or pinnately decompound and often fernlike, their 

 divisions variously toothed, lobed or pinnatifid. I. 



Leaves entire to shallowly lobed, or pinnatifid or pinnate and the divisions or leaflets entire. 



Corolla campanulate to rotate. III. 



Corolla tubular or tubular-campanulate. IV. 



Seeds excavated on the ventral surface on each side of a salient ridge; viscid and usually ill-scented 

 desert plants. II. 



Corolla-scales wanting, the base of the filaments sometimes with a dilation or wing. V. 



Seeds transversely corrugated; ovules numerous. VI. 



I 



Perennial, or rarely biennials, often somewhat woody at base. 



Corolla pelviform to subrotate; seeds 30-60, 1-1.5 mm. long. 4. P. Bolanderi. 



Corolla campanulate to pelviform; seeds 2-18, 1.5-3 mm. long. 



Inflorescence thyrsoid; corolla marcescent; seed-markings in vertical rows. 



3. P. sericca. 



Inflorescence globose or open; corolla deciduous; seed-markings not in vertical rows. 



Calyx-lobes lanceolate to linear-oblong; corolla-lobes revolute; seeds 3-16. 



Plants 5-15 dm. tall, usually erect, glandular in the inflorescence; corolla greenish white. 



2. P. procera. 



Plants 1-3 dm. tall, usually decumbent or ascending, appressed-hirsute throughout; corolla 

 purplish blue to white. 1. P. hydrophylloides. 



Calyx-lobes oblanceolate to spatulate; corolla-lobes plane; seeds 2-4. 



Calyx-lobes spatulate, 5-6 mm. long; corolla 5-8 mm. long; branches usually decumbent or 

 prostrate. 5. P. ramosissima. 



Calyx-lobes oblanceolate, 2-3 mm. long; corolla 3-5 mm. long; branches erect or ascending. 



6. P. cinerea. 

 Annuals. 



Seeds 10-40, 0.5-0.75 mm. long. 



Basal leaves ovate, scattered; flowers sessile; corolla 5-8 mm. long and broad. 7. P. Lyonii. 

 Basal leaves oblong, rosulate; flowers long-pedicellate, the pedicels elongate and recurved; corolla 6-1 S 

 mm. long, 8-20 mm. broad. 48. P. Douglasii. 



Seeds 1-8, 1.5-3.5 mm. long. 



Calyx-lobes pinnatifid, with 3-5 oblong or oblanceolate, divergent divisions. 8. P. fioribunda. 

 Calyx-lobes entire, or one or two of them crenate and the others entire. 



Leaves simple, shallowly lobed, broad and flaccid; plants prickly-hispid throughout. 



Stamens exserted. 5-10 mm. long; style exserted, 8-12 mm. long; corolla broadly campanulate, 



5-7 mm. long and broad; coastal. 15. P. malvaefoHa. 



Stamens included, 2-3 mm. long; style included, 2-3 mm. long; corolla narrowly campanulate, 

 4-5 mm. long and broad; inland. 16. P. Rattanii. 



Leaves pinnate or pinnatifid, often deeply dissected and fernlike, in some shade forms broad, flac- 

 cid, and merely lobed. 



Calyx-lobes markedly enlarged in fruit, oblong-lanceolate to ovate, subcoriaceous and strongly 

 venose. 



Stamens about as long as the pelviform corolla; corolla 8-12 mm. long and broad, blue with 

 a lighter center. 17. P. ciliata. 



Stamens much shorter than the campanulate-funnelform corolla; corolla 3-4 mm. long, 

 2-3 mm. broad, white or pale blue. 18. P. thermalis. 



Calyx-lobes neither subcoriaceous nor venose, if conspicuously enlarged, either linear or spatulate. 

 Calyx-lobes dimorphic: 2 ovate and crenate or entire, 3 lanceolate to narrowlv spatulate. 



10. P. platylob'a. 

 Calyx-lobes equal or unequal, but not dimorphic and always entire. 



Corolla lavender or white; calyx-lobes linear or linear-oblanceolate, up to 1 cm. long in 

 fruit, often conspicuously clawed and loosely enveloping the capsule. 

 Corolla broadly campanulate, 8-12 mm. long and broad, much longer than the calyx. 

 Flowers numerous, crowded; fruiting pedicels very fragile; capsules with 



pustulate bristles; mostly cismontane. 12. P. cicutaria. 



Flowers few, remote; fruiting pedicels relatively persistent; capsule hirsu- 

 tulous, scarcely bristly; deserts. 14. P. vallis-mortae. 



Corolla campanulate-funnelform, 4—7 mm. long, 3-4 mm. broad, about as long as 

 the calyx. 13. P. cryptantha. 



Corolla bluish purple to white; calyx-lobes linear to obovate, little or not at all enlarged 

 in fruit and considerably less than 1 cm. long, closely investing the capsule. 

 Cymes scattered, subsessile; calyx-lobes lanceolate to oblanceolate or obovate; 

 corolla promptly deciduous; capsule globose, 2-3 mm. long, hairy to below 

 the middle. 9. P. distans. 



Cymes approximate in pedunculate clusters; calyx-lobes linear to linear-lanceo- 

 late; corolla tardily deciduous; capsule broadly ovoid, 3-4 mm. long, hairy 

 only at apex. 11. P. tanacetifolia. 



