450 TRANS. OF THE ACAD. OP SCIENCE. 



23. J. tenuis, Willd., is one of the most common and best 

 known, but also one of the most variable species, and can 

 always be readily distinguished from all the allied ones by its 

 flat leaves, which only in the narrow-leaved forms are on the 

 margin slightly involute ; by the lanceolate, subulate sepals 

 of equal length, which somewhat exceed the ovate, retuse 

 capsule, and principally by the small, mostly oblique, delicately 

 lineolate seeds, with distinct but short, whitish appendages; 

 they are very similar to those of J. efusus, and are mostly 

 0.25-0.28, rarely only 0.20 line long. 



Notwitstanding the great variability in the size of the plant 

 (from a few inches to two feet), in the size and development 

 of the one, two, or even three spathes, and in the size and full- 

 ness of the inflorescence (1-5 or 6 inches in length), I can 

 distinguish only the following well marked varieties : 



Var. (3. secundus, ramis paniculaa spatham excedentibus 

 erectis incurvis ; floribus minoribus seeundis. — J. secunchis, 

 Poir. 



Var. y. congestus, ramis panicula? spatha brevioribus abbre- 

 viatis ; floribus fere in capitulum congestis ; sepalis fusco-stri- 

 atis ; capsula e stramineo fusca. 



The legitimate J. tenuis is found over the whole country, 

 from the Atlantic to the Pacific, and south into the tropical 

 parts of America, in the West Indies, and in western Europe. 

 — The interesting and quite distinct looking variety with 

 unilateral flowers has usually 4 or 5, but sometimes even 6 

 or 7, flowers on a single* branch, which is curved inward and 

 not backward, as is the case in Borraginem, the one-sided 

 inflorescence of which bears a great analogy to that of 

 our plant. Most of the specimens of this variety which fell 

 under my observation were obtained in Pennsylvania, and a 

 few in New England; forms approaching it are found in 

 other regions also. — The variety 7, which occurs in California 

 (San Francisco, Bolander; Monterey, Brewer") and in Colo- 

 rado, Hall, is very striking ; its apparent heads, 4-9 lines in 

 diameter and nearly as high, bear flowers a little larger than 

 ordinary, with darker colored sepals. The seeds of both 

 varieties are undistinguishable from those of the common 

 plant. 



24. J. dichotomus, Elliott, Sketch, 1,406; Chap. Flor. 493; 

 though closely allied to the preceding, is a well marked 

 species, and would not have so often been confounded with 

 it, if the characters, as given by Elliott, had not been over- 

 looked. The terete leaves, which are marked by a shallow 

 groove on their upper side, distinguish it at once, even when 



* These branches are only apparently single axes, for in reality they 

 are formed of many short, successive branches. 



