“the fruit may indicate some such common relationship, but 
402 >. BOTANICAL GAZETTE. | December, 
involucels more or less prominent.—Wet ground, Massachu- 
setts to Florida, and westward to the plains. Runs through 
many intermediate forms into the 
Var. Nuttallii, with umbels 15 to 30-rayed, involucral.) 
leaves usually entire, and involucels minute (D. /Vuttalla 
DC.).—In the lower Mississippi Valley. 
Although var. Nuttallii is set apart as'a variety, it must 
be understood to include only extreme forms. ere are 
many forms which intermediate and combine the characters of 
the species and variety. The number of rays is very incon- 
stant, while the involucral leaves are frequently cleft and 
entire in different umbels on the same plant, and the involu- 
cels may be as prominent in forms which are var. Nuttallii 
In every other respect, as in true D. capillacea, or they may 
e very minute in the species itself. Fruit characters entirely 
fail to give any distinction. As for the form called D. capil 
lacea, var. costata DC., we are at a loss to discover even any 
varietal characters. In a large series of specimens so la- 
beled from different herbaria we fail to find the slightest dis- 
tinction from D. capillacea; and if there is a var. costata we 
have never seen it, nor is it known to our best collectors. 
The two following genera have been referred to Apium 
L.: Leptocaulis by Bentham and Hooker, and Ammoselinum. 
by Gray. The general habit of the plants and the size of 
a~study of their fruit structure reveals differences fully as 
great as obtain among other genera of Umbellifer& as at 
present considered. In fact, a glance at the figures repr 
senting these two genera and Apium on plate xvii will show 
a diversity of fruit characters greater than exists among any 
other three allied genera we have figured. Including hes 
three genera under one would be entirely inconsistent with 
the definition of other genera of Umbellifere. We therefore 
restore the genera as follows: 
y» 
what 
with face more or less concave: stylopodium conical br 
109-114). — Very slender I ° 
