THE GENUS ISOETES IN NORTH AMERICA. 453 
§ 2. Morpnotocy or Isofres, 
The species of /soétes are the simplest vascular plants known. They consist of a short trunk? 
with root-fibres at its base and leaves on its top, normally without branching and without any 
axillary productions? 
in West Canada. In the same =~ Wm. M. Canby dis- 
covered in Maryland I. saccHara 
Leidy and Porter ee I. lacustris near the 
outlet of Lake Superior, In the same year I. Tuckermani 
was rediscovered near Boston by Wm. Boott. 
Charles Wright discovered I, CuBANA in Eastern 
Cuba. In the same year H. Bolander found two new species 
in the Sierra Nevada of California, I. BoLanpEri and I 
PYG — 
867. Wm. Boott got near Boston the ines named 
a him I, Boor I, now kn s I. echinospora, var. Boottti 
m. M. Canby sorely on the Stone Mountain 
in a the curious little iL MELANOSPORA 
tallii on the ileal eves: and in 1872 traced J. sitenie 
ae ed Texas. 
T. P. James got Z. echinospora, var. Brauntt, in 
iis ie and C, C. vies found JL. Bolanderi in Yellow- 
stone Lake, in Wyo 
75. G. D. Butle . “discovered in the pe (361 (4)] 
Territory the species named for him I. BurLE 
with it a new locality for I. melanopoda. 
1878. C. G. Pringle found in Lake Champlain the form 
of = echinospora, which I have designated as var. ROBUSTA. 
1879, M. E. Jones met with Z. Bolanderi in Utah. 
1880. A. uae discovered near Nashville, Tenn., 
I, Butleri, var. 1MMACULATA. 
1881. I collected Z. lacustris, var. PAUPERCULA, in Grand 
Lake, Middle Park, Colorado ; and C. G. Pringle found the 
sam. 
BLICATION. — 1753. Linneus published in 
Species Plantarum, ed. i., his Jsoées lacustris, the only 
cies known to him. 
Neither Michaux nor any of the older writers on Ameri- 
can plants knew of any North American Jsoéles. 
1816. Pursh, Fl. Am. Sept. ii. 671, mentions nat S Zacus- 
probably J. echinospora, var. a the only species thus 
far known from that region 
uttall, Gen. ii. 253, has ‘* J. lacustris” from the 
miry shores of the aun: near cep which can- 
. 14 
ria ; 
tat. a the same year Barton, FI. * Philad. ii. 213, has ‘‘ 7. 
lacustris”? from Philadelphia, which may include both J. ri- 
paria a I. Engelmanni. 
1824. Elliott knows no Isoétes. 
1826. Torrey, Comp. Fl. North. & Middle States, gives 
as habitat of ‘‘615, I. lacustris,” bottoms of lakes, evidently 
without having himself seen it. In the Flora Detien of the 
same year Darlington does not mention the ge 
827. Sprengel, Syst. Plant. iv. 9, aia nai I. lacus- 
tris with ee varieties. 
1833. Beck, in his Botany, repeats Pursh’s and Nuttall’s 
localities. 
1840. Hooker, Fl. Bor.-Am. ii. 268, mentions ‘‘Z. Jacus- 
tris” from the Saskatchewan. This may be the 
true lacustris or a form of —— either of [362 (5)] 
which may be expected in those region. 
_been very muc 
1843. Torrey, Flora of New York, ii. 514, “JZ. lacus- 
tris,” a mere repetition of Pursh’s statement. 
1844, ry investigates the genus, which until then had 
mannt, A. Br., from Missouri, and J. 
Shite from Florida. 
847. The Amer. Journ. Arts & Sciences, n. ser. iii. 52, 
Pp sis a seen of the above notice. 
un the first edition of the Manual Bot. 
riorth, "Diaalk . 640, distinguishes the then known 
northern species, I. ris, I. riparia, er I. Engelma 
1853. Darlington, Fl, " Caat ed. ii, p. 402, mentions “E 
lacustris” as growing in shallow ponds in his district. is 
must refer to I. Engelmannt, the only species growing there 
were rE 
6. ray, Manual, ed. ii., gives an almost verbal 
mint of the a edition. 
Chapman, Fl. South. States, p. 602, dese tribes J. 
as growing in ‘‘ lakes and clear streams” in Middle 
and West Florida. In the same year E. Tatnall, Cat. Pl. 
Newcastle Co., Delaware, enumerates I. riparia and I. Engel- 
manni, both of which names here probably stand for the latter, 
Durieu de Maisonneuve, Prof. of Botany at Bor- 
Ta: i. 
‘el 
(or 
os 
a 
, ds Oo 2Oy 102, ‘indicates four 
American Isoétes : se pc Massachusetts, Braunii from 
New Hampshire, macrospora from the Catskill Mountains, 
and melanopoda, Gay (or Gay and Durieu), from Illinois. In 
the same year A. Braun published a most important treatise 
on the genus in his account of the Fscttes of the Island of Sar- 
1867. In the fifth edition of Gray's Manah (363 (6)] 
p- 676, I for — first time published 
as an American species, differing in shes varieties from the 
European type — var. Braunii (I. Braunii, Dur.), var. mu- 
ricata ricata, Dur.), and var. Boottii (I. Boottii, A. 
Braun in litt.), all of them from the cage States ; 
so I. Tuckermani, A. Braun aes iisotte, 
and J. saccharata, eo ps 
1874. In Dr. Parry nical «Scala in Western 
Wyoming, Am. N aturalist viii. 214, 215, I gave an account 
of the three western species : J. Bolanderi, oo ; I. pyg- 
mea, Engelm., and J. Nuttaltit, A. Br. in 
1877. My notice of Z. melanospora, oe. from Georgia 
was published in the Trans. Acad. Sci. St. Louis, iii, 395, note. 
1878. In Coulter's Botan. Gazette for r January, p. 1, I 
gave an account of I. Buileri, Engelm., found in the Indian 
of the structure of the trunk is 
given by H. Mohl in aa xiv. (1840)181, and a the whole 
plant and its morphology by A. Braun in the Jsoé/es der Inse 
Sardinien, Monatsber. d. beth Acad. Wissense = 1864 
mormally the Isoées trunk has been seen divided, 
