XXVII. A SYNONYMIC CONSPECTUS OF THE NA- 

 TIVE AND GARDEN THALICTRUMS OF 

 NORTH AMERICA. 



K. C. DAVIS. 



The name Thalictrwn (Linn. Sp. PI. 545. 1753) is prob- 

 ably from Thallo, to grow green, and has reference to the 

 young shoots which are of such a bright green color. 



This group includes several forms which are well suited for 

 the mixed border and rock garden, and the robust forms are 

 well placed in the wild garden. Many are very hardy, and 

 only the more southern forms of those given below are at all 

 tender. Thalictrums are valued for their healthy heads of 

 flowers, contrasted with their handsome stems and leaves which 

 are often of a purple cast. They may be propagated by seed 

 or by division of roots in early spring just as growth begins. 

 Any good loamy soil will suit them if well drained. 



The latest monograph of the genus was in 1885, by LeCoyer, 

 in Bull. Soc. Roy. de Bot. de Beige, where he describes 69 

 species. In 1886 Wm. Trelease published a fine treatment of 

 "North American species of Thalictrum" in Proc. Bost. Soc. 

 Nat. Hist. 23 : 293-304, in which he recognized eleven species 

 and four varieties north of Mexico. His treatment is rather 

 closely followed by Robinson in Gray's Synop. Fl. 1895. Since 

 that time at least ten new species have been described chiefly 

 from Mexico several of which are by J. N. Rose in Contr. U. 

 S. Natl. Herb. 5 : 185, October 31, 1899. Only five have been 

 introduced to our gardens from other countries. 



Erect perennial herbs : leaves ternately compound and de- 

 compound ; stem leaves alternate : flowers dioecious, polyg- 

 amous, or perfect in some species, rather small, generally 

 greenish-white or sometimes purple or yellow, borne in a 

 panicle or loose raceme ; sepals 4 or 5, deciduous ; petals want- 

 ing ; stamens many, showy ; carpels usually few, i-seeded. 



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