er Be 
I find on all specimens sent of the Fall generation, even 
the very young ones, plates, which are cut by a deep eines 
2 lobes and tubers N Ya below the leaf-carrying part of 
the short stem,a tuber, which looked at superficially reminds one 
of the double-tubers of many orchids. Such a tuber formation,which 
protrudes strongly toward the bottom, is entirely foreien to our 
europaean Isoetes, and known to me only for I. riparia. Does one 
find specimens with such tubers also in Spring (May- June) ? That 
could possibly be a proof that some specimenddo not develop from 
spores until Spring !? Because it seems that this tuber is being 
shed totally after the rest-period without ever being resurrected 
in this form. The specimens collected at the end of May,which I was 
able to examine, have below an.almost flat stem divided by a small 
Eee into 2 semicircular planes. Of course I would much desire 
to examine large numbers of specimens and also your reports about 
the status of livine plants, 
One cannot Beam the form of the stem (rootstock) from 
the dried condition Er, sacrificing many specimens, if it 
is broader than high or vice versa, if the upper poart is elevated, 
flat or depressed. Please examine this on living materialand dry for 
me specimens, which have been disected lengthwise,and that in two 
ways: in the direction of the en and at right angle to it. 
Such specimens show the form even when dried, but cuts in both di- 
rections are. needed. 
Your description od the very first development of the .germina- 
ting plantlets does not seem to be quite correct,but considering the 
minuteness of the first development observation without hish magrri- 
- re 
fication seems impossible. I.melanospera has the smallest spores of 
all Isoetes species.These have a rounded base and a 3-sided surface: 
The ejaculation of the spores occurs along the 3 ridges during ger- 
10 MISSOURI 
. BOTANICAL 
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