266 COISTTRIBUTIOISrS FROM THE NATIONAL. HERBARIUM. 



Brittle erect shrub, 60 cm, high or less ; leaves opposite, linear, fleshy ; flowers 

 in terminal cjmes ; fruit a capsule. 



38. RANUNCULACEAE. Buttercup Family. 



Many herbaceous representatives of the family occur in Mexico. 



1. CLEMATIS L. Sp. PI. 543. 1753. 

 Scandent shrubs; leaves opposite, pinnate; flowers often showy; fruit of 

 achenes, each with a long hairy tail. 



Several Asiatic species of Clematis are frequent in cultivation as ornamental 

 vines, and some of them are grown in Mexico. Ramirez reports the name 

 " sacamecate " as used in Hidalgo for some unidentified native species. 



Flowers solitary ; sepals erect, purplish 1. C. pitcheri. 



Flowers paniculate; sepals spreading, white. 

 Flowers polygamo-dioecious, the staminate and pistillate borne upon the 

 same plant. 



Leaflets 3, mostly 4.5 to 9 cm. long, long-acuminate 2. C. pubescens. 



Leaflets normally 5 or 7, usually less than 3.5 cm. long, obtuse or acutish. 



3. C. pauciflora. 

 Flowers dioecious. 



Leaflets all or partly 3-lobed or parted 4. C. drummondii. 



Leaflets entire or dentate or very shallowly-lobed. 



Leaflets entire, very densely yellow-sericeous 5. C. rufa. 



Leaflets entire or dentate, if entire, never densely sericeous. 

 Leaflets entire or with a few narrow acute teeth, glabrous or thinly 



sericeous beneath, usually rounded at base 6. C. dioica. 



Leaflets with few or numerous broad, obtuse or rounded teeth, often 

 densely sericeous or pilose beneath, frequently cordate at base. 

 Leaflets large, mostly 6 to 10 cm. long, usually densely pilose or 



sericeous beneath 7. C. grossa. 



Leaflets mostly less than 4 cm. long, thinly sericeous or glabrate be- 

 neath 8. C. ligusticifolia. 



1. Clematis pitcheri Torr. & Gray, Fl. N. Amer. 1 : 10. 1839. 



Clematis filifera Benth. PL Hartw. 285. 1848. ^ 



Clematis fliifcra incisa Hemsl. Biol. Centr. Amer. Bot. 1:2. 1879. 



Clematis pitcheri filifera Robinson in A. Gray, Syn. Fl. 1 ^: 6. 1895. 



Viorna pitcheri Britton in Britt. & Brown, Illustr. Fl. ed. 2. 2: 123. 1913. 



Coahuila to Sinaloa and Hidalgo. Texas to Nebraska and Indiana. 



Shrub with reddish stems, sparsely pubescent: leaflets ovate, with prominent 

 veins, acute or acutish ; flowers about 2.5 cm. long, with thick leathery sepals. 

 " Barba de viejo " ( Sinaloa ) . 



The specimens are somewhat variable, but apparently they represent a single 

 species. This plant is reported by Sess^ and Mociiio ' as Clematis viorna, a 

 species native of the eastern United States. 



2. Clematis pubescens Benth. PI. Hartw. 5. 1839. 

 Guanajuato (type locality) to Oaxaca. 



Leaflets 5 to 9 cm. long, long-acuminate, sparsely dentate or entire; sepals 

 about 8 mm. long. 



3. Clematis pauciflora Nutt. ; Torr. & Gray, Fl. N. Amer. 1: 9. 1838. 

 Baja California; reported from Sonora. California. 



Plants nearly glabrous; sepals about 2 cm. long; achenes glabrous. 

 A specimen from western Chihuahua probably belongs here also. 



' PL Nov. Hisp. ed. 2. 85. 1893. 



