451 
TYPHACEJE. (CAT-TAIL FAMILY.) 
nearly flat ; stam. and pist. parts of the spike approximate or almost 
continuous. —Borders of ponds, &c., common. July. — Stem 4°-5° 
high ; the leaves as long, and §' wide. Fruiting spike brownish on 
the surface, 1' thick. 
2. T. aiigustifolia, L. (Narrow-leaved or Small Cat¬ 
tail.) Leaves channelled towards the base , narrowly linear ; stam. and 
pist. parts of the spike usually separated by a considerable interval.— 
In similar places with the last; a rarer and smaller plant. 
2. SPABGANUJM, Tourn. Burr-reed. 
Flowers collected in separate dense spherical heads, scattered 
along the summit of the stem, subtended by leaf-like bracts, the 
upper ones sterile, consisting merely of stamens, with minute 
scales irregularly interposed ; the lower or fertile larger, consist¬ 
ing of numerous sessile pistils, each surrounded by 3 - 6 scales 
much like a calyx. Fruit nut-like when mature, 1-2-celled._ 
Roots fibrous. Stems simple or branching, sheathed below by 
the base of the linear leaves. (Name from cnrdpyavov, a fillet , 
from the ribbon-like leaves.) 
1. S. ramosum, Hudson. (Great Burr-reed.) Stem erect, 
branching above; leaves triangular at the base, the sides concave] 
scales of the fertile heads thickened and dilated above; stigma linear] 
longer than the style (stigmas often 2). —Borders of ponds and ditches’ 
common. July, Aug. —Stem 2° or more high: leaves l°-2° Ion*’ 
jP- h! wide, thickish. 
2. S. Americannm, Nutt. (Smaller Burr-reed.) Stem 
erect, mostly simple ; leaves triangular at the base , the sides flat ; stig¬ 
ma conical , oblong , oblique , scarcely half as long as the slender style. — 
Along small streams, &c., common. — Much smaller than the last. 
Fruit beaked with the slender style. 
3. S. nutans L. (Floating Burr-reed.) Stem weak ; 
leaves flat , thin, often floating , when they are usually elongated, nar¬ 
row, and pellucid ; heads few, the sterile 1-2; stigma oblong, shorter 
than the style. — Ponds and streams, common northward; when terres¬ 
trial low (6’ -10' high), and shorter leaved. —This genus requires 
careful study by the fruit. 
Order 112. NAIADACE^E. (Pondweed Family.) 
Immersed, aquatic plants , with jointed stems and sheath¬ 
ing stipules within the petioles , or sessile sheathing bases of 
the leaves , inconspicuous mono - dioecious or perfect flowers , 
