4. Collomia NuTT. 



About 13 species native to temperate North America and South America, 



1. Collomia linearis Nutt. Fig. 645. 



Annual, to 6 dm. tall, usually much less, finely puberulent or in part subglabrous 

 below, the pubescence becoming longer and glandular or viscid above; stems simple 

 and unbranched or with several or many short or elongate axillary branches, the 

 main stem and each of the branches terminating in a dense leafy-bracteate cluster 

 of essentially sessile flowers; leaves numerous, sessile or nearly so, nearly all alter- 

 nate, lanceolate to linear, entire. 1-7 cm. long, to about I cm. wide, those subtend- 

 ing the flower clusters often relatively broader than the others; calyx lobes narrowly 

 triangular, acute, herbaceous. 1.5-3 mm. long at anthesis. commonly 3-4 mm. 

 long in fruit; corolla pink or bluish to white, 8-15 mm. long, with slender tube 

 and short lobes 1.5-3 mm. long; filaments unequally inserted, about 1 mm. long 

 or less; ovules 1 in each cell of ovary. 



In wet meadows and wet soil on edge of ponds and lakes, in N.M. (Rio Arriba, 

 San Juan. San Miguel, Santa Fe and Taos cos.) and Ariz. (Apache and Coconino 

 COS.), June-Sept.; N.B. to B.C., s. to N.M., Ariz, and Calif. 



5. Microsteris Greene 

 A monotypic genus. 



1. Microsteris gracilis (Hook.) Greene 



Annual herb to about 8 cm. tall, much-branched at maturity, commonly as broad 

 as high or broader, puberulent or glandular-puberulent at least above; leaves mostly 

 opposite, linear to linear-lanceolate or elliptic, sometimes the lower ones obovate, 

 to about 5 cm. long and 8 mm. wide; flowers mostly in pairs at the ends of the stem 

 and branches, one subsessile, the other evidently pedicellate, or sometimes borne 

 singly; corolla salverform, 5-10 mm. long, the lobes 1-2.5 mm. long, with white 

 or yellowish tube and pink to lavender limb; stamens inserted at different levels; 

 ovules usually solitary in each cell of ovary. M. micrantha (Kell.) Greene. 



Moist or wet soil about springs and along streams, in wet meadows and on 

 open grassy slopes, in N. M. (Bernalillo and Rio Arriba cos.) and Ariz. (Apache 

 to Mohave, s. to Santa Cruz and Pima cos.), Feb.-June; Mont, to Alas., s. to N.M., 

 Ariz, and Baja Calif.; S.A. 



Fam. 113. Hydrophyllaceae R. Br. Waterleaf Family 



Herbs, less commonly shrubs, with alternate or opposite entire to variously 

 divided or compound exstipulate leaves; flowers regular, perfect, 5-merous, gamo- 

 petalous. cymose to solitary; calyx deeply lobed; corolla tubular to rotate but 

 usually campanulate; stamens epipetalous, as many as the corolla lobes and 

 alternate with them, usually with a pair of scales at the base of each filament; 

 ovary 1- or 2-celled, usually free from calyx; fruit a few- to many-seeded capsule. 



About 300 species in 18 genera, chiefly in the warm-temperate regions of North 

 America and South America. 



1. Leaves (at least some) variously toothed, lobed or divided (2) 



1. Leaves always entire (4) 



2(1). Delicate annual herb; flowers solitary or several in a terminal non-scorpioid 

 cyme 1. ElUsia 



2. Rather coarse perennials or biennials; flowers numerous in scorpioid open or 



congested cymes (3) 



1375 



