1915] Fernald and Wiegand,— Genus Euphrasia 183 
editors of Index Kewensis and by recent students of the genus, it was 
not until the appearance of Wettstein’s Monographie in 1896 that it 
was recognized that in North America Euphrasia consists of several 
distinct species, most of them not satisfactorily referable to Old 
World species. 
Wettstein definitely recognized in North America E. americana 
Wettstein, Z. latifolia Pursh, in part (E. arctica Lange), E. mollis 
Ledeb., E. Oakesii Wettstein, E. Rostkoviana Hayne and, with doubt, 
E. hirtella Jordan. In 1898 Townsend added FE. canadensis! (pre- 
sumably including the Quebec plant which had been the basis of 
Wettstein’s record of E. Rostkoviana, a well marked species not 
subsequently credited to North America); and in 1901, Robinson,? 
summarizing the knowledge of the American species at that time, 
recognized seven species and two varieties: E. mollis, E. Oakesii, E. 
‘uliamsii Robinson, E. Randii Robinson, E. Randii, var. (?) Far- 
lowii Robinson, E. latifolia, E. hirtella, E. americana, and E. americana, 
var. canadensis (Townsend) Robinson. 
In subsequent publications, for instance in the 7th edition of Gray’s 
Manual, Robinson’s treatment has been only slightly modified; but ex- . 
Plorations to the northeast of the Manual range have recently brought 
together so much additional material of the genus that it has seemed 
advisable to present a new study of the Eyebrights based upon a 
Somewhat extended field-knowledge of the plants and a prolonged _ 
herbarium-study; and, although the present summary of our knowl- 
edge necessarily leaves for further consideration some problematic 
plants of which we have inadequate material, it may prove useful as 
a fresh basis for further study of the genus. 
SYNopsis oF NortTH AMERICAN SPECIES AND VARIETIES OF EUPHRASIA. 
A. Upper lip of corolla very shallowly bilobed; the lobes very short, rounded, 
entire, narrowly revolute, rare y erect: lower lip scarcely fan-shaped, 
not exceeding the upper: flowers very small, 2.2—4 (rarely 4.8) mm. long: 
bracts with blunt teeth. B. 
Inflorescence capitate or subcapitate, the flowers closely crowded, only 
the 1-4 lowest pairs of bracts becoming slightly remote in maturi C. 
C. weg whitish to lilac: nodes below the head ae leaves pubes- 
Re ee ee ee A ee 6 oe: be ee eee 6 Ree me Cee S. 
1 Townsend, Journ. Bot. xxxvi. 1, t. 381 (1898). 
2? Robinson, Ruopora, iii. 270-276 (1901). 
