NOTES. 
ON THE SYSTEMATIC POSITION OP ISOETES, L.— 
The systematic position of this genus has been the subject of much 
speculation on the part of botanists. By some it has been placed 
among the Phanerogams 1 , by others among the Mosses 2 , and by 
the majority among the Vascular Cryptogams, the last being un- 
doubtedly its true position. There has also been considerable 
difference of opinion as to its place among the Vascular Cryptogams. 
The earlier botanists all associate Isoetes with Pilularia and Marsilea. 
Thus Linnaeus 3 associates these genera as a group of the Filices 
having * fructificationes radicates! and Gleditsch 4 assigns to Isoetes 
a similar position. The affinity of Isoetes with Pilularia , Marsilea , 
Salvinia, and Azolla, is affirmed more definitely by Willdenow 5 , 
who associates them in the group Hydropterides ; and by Batsch 6 , 
who unites these genera in the group Rhizocarpae, as does also 
Bischoff 7 . Bartling 8 takes the same view, classifying the Rhizocarpae 
into the three orders, Salviniaceae, Marsiliaceae, and Isoeteae. 
On the other hand, De Candolle 9 removes Isoetes from the Rhizo- 
carpeae, the group being now termed Rhizospermae, and incorporates 
it with the Lycopodiaceae, on the following grounds : * Ce genre 
semble se rapprocher, par son port, des rhizospermes, mais il touche 
rdellement aux lycopodes; i° par ses fructifications axillaires, et non 
1 Reichenbach (Conspectus, 1828) places Isoetes together with Potamogetoneae 
and Aroideae in a group (which he terms Limnobiae. Adanson (Fam. des Plantes, 
1763) makes it a genus of Aroideae. 
2 Dillenius (Hist. Muse. 1741) places Isoetes , together with Pilularia and 
Subularia in the Musci, under the name Calamaria. B. Jussieu (Ht. Trian. 1759) 
also places it among the Mosses. 
3 Linnaeus, Systema Vegetabilium, 1751. 
4 Gleditsch, Syst. Plant. 1764. 
5 Willdenow, Bern. Farrenkrauter, 1802; Species Plantarum, t. v, 1810. 
6 Batsch, Tab. affinitatum Regni Vegetabilis, 1802. 
7 Bischoff, Die Kryptogamischen Gewaechse, 1828. 
8 Bartling, Ordines Naturales Plantarum, 1 830. 
9 Lamarck et A. P. de Candolle, Flore Franjaise, t. ii, 1815 (Lycopodiaceae, 
fam. Monocotyledonum cryptogamarum). 
