1922] SEARS—TARAXACUM 427 
HANDEL-MazeErTTI (10) notes a marked difference in the rate at 
which oldest leaves die away and leave their bases, considering it a 
specific characteristic. 
As to segmentation, GOEBEL (9) classifies Taraxacum with 
those plants which produce first entire, then dissected leaves, but 
quotes evidence that segmentation is “richer” in temperate than 
arctic forms, and in ‘“‘well-nourished ” plants than in “half-starved”’ 
meadow-moor forms. DEVARIGNY, as quoted by Morean (14), 
places his own construction upon the matter by attributing the 
dissection to dry soil conditions and entire leaves to hydrophytic 
environment. FRANK (8) states that leaf development is basi- 
petal, the tip segment developing first. SrorK (17) found that 
uniform culture conditions upon seedlings (of identical age) produce 
rather uniform leaf type, regardless of leaf form extremes in the 
parents. 
ScAPE.—The normal course of changes in length and position 
throughout flowering and fruiting are well known (15). FRANK 
states that in alpine species the scape is longer in crevice plants 
than in those growing exposed. 
INFLORESCENCE.—Fasciation is admittedly a nonheritable 
character, and was determined by ScHoRBATOW (16) to be due td 
mechanical pressure during the period of most active flowering, 
“the third year.’ 
Bracts.—In taxonomic works these rank highly as criteria, 
the characteristics used being number, color, size, form, and 
position. Nevertheless, considerable variability is admitted. 
HANDEL-MazeEtti notes that infection by Synchitrium taraxact 
converted the outer bracts of 7. vulgare into those typical for 
T. alpinum. He also speaks of the great variation in corniculi in 
many species. FERNALD (7) found very complete intergrades 
between 7. vulgare and T. palustre in bracts, as well as other char- 
acters. SrorK reports that uniform culture conditions, produce 
great uniformity in seedlings from parents with widely different 
bract characters. 
FLowERS.—HANDEL-MAzETTI uses approximate flower number 
as a specific criterion,‘and states that flower color is undoubtedly a 
trustworthy character, although useless in dealing with herbarium 
