396 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



72. CONVOIVTJIACEAE. Morning-glory Family. 



1. CONVOLVTJLTJS L. 



1. Convolvulus arvensis L. Bindweed. Reported from Belton by Jones. 

 Native of Eur.; naturalized as a weed in N. Amer. — Slender prostrate perennial, 

 glabrous or nearly so; leaves ol)long, 1 to 5 cm. long, obtuse, entire, but with a lobe 

 on each side at the base; flowers solitary in the leaf axils; corolla 1.5 to 2 cm. long, 

 funnel-shaped, white or pink; fruit a capsule. 



73. POLEMOmACEAE. Phlox Family. 



Annual or perennial herbs; leaves opposite or alternate, entire, lobed, or pinnate; 

 sepals 5, partly united; corolla 5-lobed; stamens 5, attached to the corolla tube; fruit 

 a 3-celled capsule. 

 Leaves pinnate or deeply lobed. 



Leaves pinnate, with rounded leaflets; plants perennial; flowers blue. 



1. POLEMONITJM. 

 Leaves divided into linear or threadlike lobes; plants annual; flowers white. 



Flowers sessile; lobes of leaves stiff, with spiny tips ... 2. NAVARRETIA. 

 Flowers slender-stalked; lobes of leaves thin, not spiny- tipped. 



6. LINANTHUS. 

 Leaves entire. 



Plants perennial, forming dense mats or tufts; corolla white, 1 to 1.5 cm. l)road. 



3. PHLOX. 

 Plants annual, not tufted; corolla pink or piurplish, much less than 1 cm. broad. 



Leaves alternate 4. COLLOMIA. 



Leaves, except the uppermost, opposite 5. MICROSTERIS. 



1. POLEMONITJM L. 



Perennials, more or less hairy; flowers in loose or dense clusters, blue. 



Leaflets opposite, not sticky; corolla 7 to 9 mm. long 1. P. parvifolium. 



Leaflets whorled, very sticky; corolla 15 to 20 mm. long 2. P. viscosum. 



1. Polemonium parvifolium Nutt. Jacob's-ladder. Common at nearly all alti- 

 tudes, at least on the east slope, in woods, thickets, or meadows, or on open slopes. 

 Alta. to Wyo.— Plants 10 to 30 cm. high, usually in dense clumps; leaflets 11 to 25 or 

 more, 2 to 10 mm. long. 



2. Polemonium viscosum Nutt. Skunk-plaxt. Common on rock slides above 

 timber line; sometimes found on moist rocky slopes near snow banks at middle alti- 

 tudes. Alta. to Wyo. and Utah. — Plants 5 to 10 cm. high, forming dense clumps, 

 extremely viscid; leaflets numerous, 1 to 4 mm. long; flowers in a dense sticky 

 cluster. 



The plant has a heavy odor, which strongly suggests a skunk ; because of its stickines.« 

 it is unpleasant to handle. The withered corollas often persist for some time. 



2. NAVARRETIA Ruiz & Pa v. 



1. Navarretia minima Nutt. Pincushion plant. About dried-up pools on 

 prairie at east entrance. Wash, to Calif., Ariz., and Nebr. — Plants annual, 1 to 4 cm. 

 high, each one forming dense rounded mass; leaves divided into numerous slender 

 stiff sharp-pointed lobes; flowers crowded at the ends of the stems; corolla white, 7 

 mm. long. 



An inconspicuous little plant. Upon trying to pull up the plants, one finds the 

 leaf lobes as prickly as pin points. 



