960 CONVOLVULACEAE 



long as the calyx ; lobes narrow, lanceolate, curling back, about as long as the tube : fila- 

 ments glabrous. 



In saline soil, Texas to southern California and tropical America. Spring and summer. 



2. Cressa aphylla Heller. Foliage cinereous. Stems erect, 1-2 dm. tall, destitute 

 of typical leaves, branched from near the base and throughout : leaves reduced to small 

 scales : pedicels about 1 ram. long : bracts barely as long as the calyxes, lanceolate to 

 ovate-lanceolate : sepals closely pubescent, oblong-lanceolate or elliptic, 3-4 mm. long, 

 acute or slightly acuminate : corolla yellowish white ; tube as long as the calyx ; lobes 

 ovate, shorter than the tube : filaments pubescent below the middle. 



In dry or sandy soil, Texas. Spring. 



3. E VOLVULUS L. 



Annual or perennial caulescent herbs, with shaggy or appressed pubescence. Leaves 

 alternate : blades entire. Flowers solitary in the axils, or in terminal racemes or panicles. 

 Calyx usually pedicelled : sepals 5, nearly equal. Corolla white, pink or blue, funnel- 

 form, campanulate or rotate : limb plaited, 5-angled or 5-lobed. Stamens 5 : filaments 

 filiform. Ovary 2-celled, globular. Styles distinct, each 2-cleft. Stigmas slender. 

 Ovules few. Capsules but little longer than broad, 2-4-valved. Seeds 1-4, glabrous. 

 The plants flower from spring to fall. 



Peduncles as long as the leaves or longer. 



Leaf-blades glabrous or nearly so at maturity. 1. E. mucronatus. 



Leaf-blades copiously pubescent. 2. E. aMnoidec. 



Peduncles wanting or very short : pedicels shorter than the leaves. 



Leaf-blades glabrous above. 3. E. sericcus. 



Leaf-blades copiously pubescent on both sides. 



Pubescence silky : sepals acute, erect or nearly so. 4. E. moUis. 



Pubescence shaggy : sepals acuminate, the tips spreading. 5. E. piloms. 



1. Evolvulus mucronatus Sw. Silky when young, soon glabrate. Stems branched 

 at the base ; branches spreading or prostrate, 1-4 dm. long, very slender : leaf-blades 

 oblong to obovate, 1-1.5 cm. long, mucronate, entire, narrowed into short petioles: pedun- 

 cles as long as the leaves or longer : pedicels shorter and stouter than, the peduncles : 

 sepals glabrate, 3-4.5 mm. long, oblong to oblong-ovate, acute : corolla rotate, about 1 cm. 

 broad : capsules subglobose, 2-2.5 mm. in diameter. 



In sandy soil, Florida and the West Indies. 



2. Evolvulus alsinoides L. Strigillose and more or less densely villous-hirsute. 

 Stems branched at the base ; branches decumbent or prostrate, 1-6 dm. long, slender : 

 leaf-blades oblong-oval or oblong-lanceolate, 6-25 mm. long, acute, entire, narrowed into 

 short petioles : peduncles as long as the leaves or longer : pedicels recurved or refracted : 

 sepals 2-4 mm. long, ovate or oblong-lanceolete, acute : corolla rotate, 8-12 mm. broad : 

 capsules subglobose, 3-4 mm. in diameter. 



In sandy soil, Florida to Texas. 



3. Evolvulus sericeus Sw. Silky. Stems branched at the base ; branches ascend- 

 ing or decumbent, 1-3 dm. long, slender, commonly zigzag : leaf-blades linear to oblong, 

 1-2.5 cm. long, acute at the ends, glabrous above, sessile : pedicels shorter than the 

 calyxes, slightly thickened upward : sepals silky, 4-6 mm. long, oblong to broadly elliptic, 

 acute to acuminate : corolla white or blue, rotate, 8-10 mm. broad : capsules subglobose, 

 3-4 mm. in diameter. 



In low grounds, Georgia and Florida to Texas and Arizona. Throughout tropical America. 



4. Evolvulus mollis Small. Silky. Stems branched at the base ; branches ascend- 

 ing or decumbent, 5-20 cm. long, slender : leaf -blades linear to linear-oblong or linear- 

 lanceolate, 1-2.5 cm. long, acute, sometimes scythe-shaped, entire, sessile or nearly so : 

 pedicels shorter than the calyxes : sepals more or less densely lanuginose, 4-6 mm. long 

 oblong or lanceolate, 4-5 mm. long, narrowly acute, erect or nearly so : corolla bluish, 10- 

 14 mm. broad : capsules globose-ovoid, 4-5 mm. in diameter. 



In dry soil, Texas. 



5. Evolvulus pilosus Nutt. Densely silky-hirsute, silvery, becoming tawny or fer- 

 ruginous. Stems much branched at the base ; branches ascending or spreading, 15-25 cm. 

 long, stout: leaf-blades oblong or broadest above the middle or belovy it, 1-1.5 cm. long, 

 acute, densely pubescent on both sides, sessile or short-petioled : pedicels curved, shorter 

 than the calyxes, densely pubescent : sepals silky, 6-8 mm. long, linear-lanceolate, 5-6 mm. 

 long, long-acuminate, the tips widely spreading : corolla about 1 cm. broad : capsules about 

 3 mm. long. [E. argentcus Pursh.] 



In dry soil, Kansas to Colorado, south to Texas, Arizona and Mexico. Also on Key West, Florida. 



