of France, and in most warm climates, it bears longer and nar¬ 
rower leaves than with us, and becomes the Isoetes setacea of 
Bose, I. velata, A. Braun. The same variety occurs in Sardinia, 
Sicily, in Algeria, and in the Madras Peninsula and Afghanistan 
(/. Coromandeliana, Linn.). /. adspersa of A. Braun (in Ba- 
lansa, PL d’Algerie) is a fine and very slender-leaved form of the 
same, as is a specimen of an Isoetes in my herbarium from Swan 
River {Drummond, n. 989 and 990); and again from Darter, 
discovered at Nape, tropical Africa (n. 1020). The species is 
common in North America; Dr. Engelmann has found what 
has been called, one, I. riparia, Engelm., and another, I. Dngel- 
manni , Braun. From British Columbia and Northern California 
Mr. Nuttall has sent to me his Isoetes opaca (I believe a MS. 
name), which seems to be identical with our I. lacustris, as 
I do Isoetes Matinveniana of De Notaris from Piedmont, and 
I. echinospora, Dene., from Lozera. In South America speci¬ 
mens received from Spruce, Santarem, Brazil, and from the 
Missions of Duro, Brazil, Gardner , n. 5563 (and so named by 
him), are common forms of our British Quillwort. Isoetes 
lacustris, Metten. in PL Lechlerianse, n. 937, is a short, broad, 
acuminated-leaved var. from Peru. Isoetes Andina, Spruce’s 
MS., from the Quitinian Andes (without number) is pro¬ 
bably distinct in the broad, firm, rigid leaves, coriaceous and 
glossy when dry, scarcely tapering at all, but suddenly acute, and 
with a very broad rhizome. Another remarkable and I presume 
very distinct species, from mountain lakes of Tasmania, a good 
deal resembles this of Mr. Spruce; but many of the leaves are 
quite obtuse or retuse, and often tipped with a very conspicuous 
and remarkable gland. 
Previous to my knowledge of the two Isoetides last mentioned, 
I had joined Dr. Arnott (see c British Flora,’ /. c.) in the remark 
that “ there is probably only one known species of the genus.” 
But since that remark was made, another remarkable Isoetes has 
been discovered, which is figured and described in our next 
Plate, and I most gladly recall that statement as incorrect. 
Plate 55. Fertile plant of Isoetes lacustris, Linn.,— natural size. Fig. 1. 
Front view of a leaf from the centre of the plant, slightly magnified, with its 
capsule. 2. The capsule removed from the leaf. 3. The same cut through 
transversely. 4. Spores or antheridia,—all more or less magnified. 5. Back view 
of an outer leaf. 6. Front view of the base. 7. Capsule removed from the leaf. 
8. The same cut through transversely. 9. Minute oblong granules or oogho- 
ridia :—all more or less magnified. 
