Group 1. Aquaticoe. Species inhabiting lakes and ponds, where
they are permanently submerged. Leaves without stomata,
accessory bast-bundles, or persistent bases.
ALil none . . . Sp. 1 -3
Veil partial . . . Sp. 4 -7
Veil complete . . Sp. 8 -9
Group 2. Subaquaticai. Species inhabiting shallow water.
Leaves with a few stomata, but without either accessory
bast-bundles or persistent bases.
Eootstock 2-lobed .
Eootstock 8-lobed .
. Sp. 1 0 -1 4
. Sp. 1 6 -1 8
Group 3. Amphibia;. Species inhabiting waters where they are
liable to be left dry. Leaves furnished with accessory
bast-bundles and abundant stomata. A few small membranous
leaf-bases occasionally persistent.
Eootstock 2-lobed . . Sp, 19 -2 4
Eootstock 3-lobed . . Sp. 2 5 -4 7
Group 4. Terrestres. Species growing in damp soil. Leaves
furnished with accessory bast-bundles and abuiidaiit
stomata. Bases of the leaves of a former year regularly
persistent in the form of blackish indurated scales outside
the new leaves . . . Sp. 4 8 -4 9
Group 1.— Aquaticoe.
1. I. TKIQUETEA A. Bi'. in ALrli. Branden. 1862, 36. 1. andina
Spruce M S S .—Eootstocki very thick (nearly 1 in. diam.), 2-lohed.
Leaves 6 0 -1 0 0 , stiffly erect, firm in texture, dull green, 2 -8 in.
4 ill. broad at the middle, with a channelled triquetrous tiq),
and a distinct crisped border reaching from the base half-way up,
without either stomata or accessory bast-buudles. Sporangia
oblong, triuicate at the apex, J i n . long, copiously dotted; veil
none. Macrospores obscurely tubercled between the ridges, more
distinctly tubercled on the lower half. Microspores smooth, brown
or white.
Hab. Ancles of Quito, Spntce ! Peru, Lechler.
2. I. G d n n i i a . Br. in Berl. Moiiatber. 1868, 5 3 5 .— Eootstock
3-lobed. Leaves 50 or more, stiffly erect, opaque, dark green,
2 -8 in. long, l-1 2 th iu. broad at the middle, narrowed suddenly at
the tip, with a short brown uncrisped border running up from the
base, without stomata or accessory bast-bundles. Sporange small,
orbicular ; veil none. Macrospores large, smooth, chalk-white.’
Microspores smooth.
Tasmania, forming large masses in the mountain-lakes, alt. 3500—
4000 ft., Ghh«, 1563 !
8. I. ELATIOK F. M. ; A. Br. iu Linnæa, xxv. (1852), 722 ; Berl.
Monat. 1868, 686. I. tasmanica F . M. ; Durieu in Bull. Bot Fr
1864, 104, ex p a r te .— Eootstock 3-lobed. Habit of 1. lacustris'.
Leaves 8 0 -5 0 , flaccid, dark green, diaphanous, reaching a foot in
length, 4 lin. broad at the middle, the lanceolate base running up
the edge as a distinct membranous unorisped border for 3 -4 in.,
without stomata or accessory bast-bundles. Sporange small,
brown, orbicular, u n sp o tted ; veil none. Maorospores small,
white, flnely granular. Microspores smooth.
Hab. Tasmania, in lakes. Archer !
4. I. LAOuBTEis Linn. ; Hook. Brit. Ferns, t. 55 ; Durieu, Bull.
Bot. France, 1861, 1 6 4 ; A. Br. in Verb. Branden. 1862, 17. I.
atrovirens T. Fries. I. macrospora Durieu. 1. Morei D. Moore.—
Eootstock 2-lobed, generally about 4 in. diam. Leaves generally
2 0 -5 0 , 3 -6 in. long, 4 -1 lin. diam. at the middle, dark green,
flaccid, diaphanous, tapering to the point, the edge deourrent from
the base, short and narrow, without stomata^ or accessory bast-
bundles. Sporangia subglobose or oblong, 4 - i hi. long, unspotted ;
veil partial. Maorospores large, white, strongly granulated.
Microspores quite smooth.
Hab. Widely spread in the lakes of Northern and the mountains of Central
E u ro p e ; rare in North America. Durieu, in Bull. Bot. Soo. Prance, xi. 102,
separates the American plant by its larger macrospores as a species as I. macrospora.
I. Morei D. Moore in Journ. Bot. 1878, 353, t. 199, from Lough Bray,
Wicklow, is a large flaccid form with leaves about a foot long. I. crassa,
setacea, and tendía of Leman and Desvaux represent three forms of this species
as to robustness of growth.
5. I. ECHINOSPOEA Durleu iu Bull. Soc. Bot. France, viii. 164;
A. Br. in Verb. Brand., 1862, 2 4 ; Bab. hi Journ. Bot. 1863,
t. 1.—Eootstock 4 - f in. diam., 2-lobed, rarely 8-lobed. Habit of
I . lacustris, but leaves more slender, generally 2 0 -5 0 , 4 -6 in. long,
about 4 lin. broad at middle, flexible, diaphanous, light green,
tapering gradually to the point, the edge decurrent from the
dilated base, narrow and short. Sporange globose or oblong, 4 m.
long, unspotted ; veil short. Macrospores middle-sized, distinctly
spinulose all over. Microspores slightly papillose.
Hab. The type widely spread in the lakes of Northern and Central Europe,
often associated with I. lacustris. In I. Braunii Durieu [I. ambigua A. Br.), of
North America, Greenland, and Iceland, the leaves are darker green, with a few
stomata, the veil larger, the sporange spotted, and the microspores smooth. In
I muricata Durieu, of New England, th e leaves are longer, the unspotted
sporange half covered by the veil, and the spinules of the macrospore shorter ;
and in I. Boottii A. Br., of Boston, U.S.A., the leaves are stiffly erect, with a few
stomata, and the maorospores ra th e r smaller, with very slender spinules.
6. I. AZOEICA Durieu; Milde F il. Fur . 278.— Eootstock probably
2-lobed. Habit of I . echinospora. Leaves 2 -3 in. long, under
4 lin. broad at the middle, ligh t green, diaphanous, without
stomata or accessory hast-hundles. Sporangia subglobose, u n spotted,
1 - l J lin. lo n g ; veil large, but partial. Microspores
middle-sized, reticulated over both halves. Microspores granulated.
Hab. Azores, in a shallow pool in the Island of Corvo, H. C. Watson 349 ;
a few specimens collected in the year 1842.
7. I. PYGMiEA F n g e lm . in Amer. Nat. 1874, 2 14.— Eootstock
2-lob’ed. Leaves 5 -1 0 , 4 -1 in. long, dark green, tapering rapidly
to the point, without stomata or accessory bast-bundles. Sporange