i 
Braun and Engelmann’s North American Equiseta. 89 
of the Wabash and Ohio, and the Mississippi near St, Louis, also 
_ on lakes and smaller streams in that region, (G. Lng: gelmann.) 
| Banks of the Missouri up to Eau-qui-coule River, (Geyer in Ni- 
 collet’s Expedition.) Also in the East Indies; Lahore, (Jacque- 
mont,) Pondicherry, (Belanger.) Varieties ?. and 7. near St. Louis, 
the first with the common form, the other with £. levigatum, 
on poorer soil. 
This stately species appears to take the place of E’. hyemale in 
the Mississippi valley, at least in its middle and southern parts. It 
reaches a size of from three or four to even six feet, (Geyer.) The 
largest specimens from Louisiana, have 44 to 48, those from the 
Ohio and from St. Louis, have all from 37 to 41 carine, and con- 
sequently leaves. The species is distinguished from #’. hyemale 
by its size, by the strictly simple row of tubercles on the ridges, 
and by the 3-carinate (not 4-carinate) leaves. It is a remarkable 
peculiarity that in old specimens, not only the teeth or points are 
deciduous, but also the upper part of the sheath itself down to 
the black girdle, giving the stems the appearance of the fossil 
Calamites, with reduced dimensions. The branches of flower- 
ing stems have usually 11 carinz, but branches of old decaying 
stems, and young sterile shoots have 17 to 25 and more carine. 
Var. 8. offers no difficulties; but y. approaches very closely, 
rather too much so, to the next species, whence the name. It 
/ has the same size and growth, but the sheaths appear to be shorter, 
their leaves never 4-carinate, and the tubercles on the carinee of 
the stem constantly in one row. ‘This variety corresponds with 
var. y. of the next species, both being much smaller than the 
common forms, and much rougher also; the roughness extending 
to the points of the leaves and sendesiig them more persistent. 
9. E. uyvemate, Linn.—Stems tall, erect, simple, rarely with 
a few branches; carine rough with two more or less distinct rows 
of tubercles ; grooves on each side with a single series of stomata ; 
vallecular air-cavities large, the carinal ones minute ; central cav- 
ity large; sheaths elongated, closely ad pressed, wis a black gir- 
dle above the base, and a black limb, consisting of about 20 (in 
the branches 9) narrowly linear, at base 1-carinate, above obsolete- 
ly 4-carinate leaves, with linear-subulate deciduous points, which 
leave a bluntly crenate margin. 
6. paLeaceum, A. Braun.—Stems smaller, sheaths with a black 
limb, but mostly without a black girdle, consisting of 10 to 12 
Vol. xtv1, No. 1.—Oct.-Dec. 1843, 
