124 BOTANICAL GAZETTE | FEBRUARY 
umbellets of the two plants is frequently aborted, when present I have 
found no exception to its sessile character in Zizia and stalked in 
Thaspium. 
As far as I have met with the two plants in this region they differ 
in their habitats. Z. aurea is very abundant, and occurs throughout in 
suitable localities, and grows indifferently in clayey and in sandy soils, 
but more vigorously in the former. 7. aureum is infrequent, and has 
always been found in clayey or loamy land, and almost always along 
streams. I have but one specimen away from streams or the vicinity 
of water, from Forest Hill, in the south part of the city. Its principal 
home is along the bluff banks of streams, or beyond the bounds of the 
flood plain. From these banks, either contiguous to the stream or 
bordering the flood plain, it spreads a little into the adjacent woods. 
In such situations I have seen it by the Kankakee river, the Des- 
plaines and some of its branches, the Calumet, and Thorn creek, one 
of its affluents, and it is likely to occur under similar conditions along 
other streams of the vicinity.— E. J. Hitt, Chicago. 
A NEW ISOETES FROM IDAHO. 
Isoetes Underwoodi, n. sp.—Leaves 18-50, rather slender, 10-16™ 
long, erect to recurved, semi-lunate or nearly helmet shaped in section, 
striate, with abundant stomata above; peripheral bast bundles gener- 
ally all four present, but sometimes one or more lacking : macrospor- 
angia dark brown: microsporangia olivaceous, elliptic to narrowly 
oblong, much pitted, 6-8"" long, slightly covered by the narrow wings 
of the velum: ligule rather narrowly triangular: macrospores bright 
white, 0.33-0.45"" thick, rough with low single or confluent tubercles : 
microspores copes shay o28™™ long, unsymmetrical, short ee on 
the edges. 
— ground, eric of pools, Paradise creek, i in and near Moscow, : 
seems to reach perfection entirely out of water. The dry lea 
look more or less round, but this is due to the sharp lateral pe 
becoming so involute as to present merely a narrow channel along the 
widest side. The air cavities are generally quite large and the walls ee 
thin. It differs much from the only other two species of this region, , 
, From the bese it oes re longer 
2 ae Nuttaltii and Z che 
This plant is hens dee: a greater part of the spring, b io : 
F 
