. TYPHAC&& 419 



tufts of soft, brownish hairs. When in fruit, the upper part of the 

 spike is a bare stalk, whilst the lower part has thickened by the enlarge- 

 ment of the nuts, still enveloped in the rusty down. 



On the margins of ponds, lakes, and watery ditches, nearly all over 

 the north temperate zone. Abundant in Britain. FL summer. [Often, 

 but erroneously, called utt-rush.] 



2. T. angustifolia, Linn. (fig. 940). Lesser R. Differs from T. 

 latifdia chiefly in the interruption in the spike between the male and the 

 female flowers, for a space varying from a few lines to an inch in length. 

 It is also usually smaller, with narrower and stiffer leaves, more con- 

 cave on the upper side, and the spikes are more slender, but all these 

 characters are very variable. 



Accompanies T. latifdia over the greater part of its area, but is not 

 so common, and scarcely extends so far north. In Britain, it occurs 

 locally from Fife and Lanark southwards, and rarely in east Ireland. 

 fl. summer. 



II. SPAEGANITJM. SPARGANIUM. 



Flowers in globular heads, placed at a distance from each other along 

 the summit of the stem, with leaf-like bracts under the lower ones. 

 Upper heads all males, consisting of stamens with minute scales irre- 

 gularly interposed ; the lower heads larger, all females, consisting of 

 sessile ovaries, each one surrounded by 3 to 6 scales, forming an irregular 

 perianth. 



A small genus, dispersed over the northern hemisphere without the 

 tropics. 



Inflorescence branched, each branch bearing more than one head . 1. S. ramosum. 

 Inflorescence simple. 



Stems and leaves erect 2. S. simplex. 



Stem weak. Leaves floating . 3. & minimum. 



1. S. ramosum, Huds. (fig. 941). Branched S., Bur-reed. Stems 

 erect, simple or branched, 2 feet high or more, sheathed below by the 

 long, linear leaves, which usually far surpass the inflorescences. These 

 form a kind of panicle at the summit of the stem, with 3 or 4 to 6 or 8 

 simple branches, each bearing 6 to 12 or even more male heads, about 

 the size of a pea till the stamens expand, when they are about 4 lines in 

 diameter ; the lower female heads are fully 6 lines in diameter, glabrous, 

 with the long linear points of the stigmas very prominent. 



On the margins of ponds, lakes, and streams, almost all over Europe 

 and Russian Asia, and a portion of North America, but scarcely reaching 

 the Arctic Circle. Extends all over Britain. PI. tummer. 



2. S. simplex, Huds. (fig. 942). Simple S. Rather smaller than S. 

 ramosum, with narrow leaves ; the flower-heads much fewer, at consider- 

 able distances from each other along the simple summit of the stem ; 

 all sessile except the lowest female, which is often on a peduncle of 1 

 to 2 inches. Flowers as in ramosum. 



In similar situations, and nearly as widely distributed as S. ramosum, 

 but not quite so common. Not nnfrequent in Britain. Fl. summer. A 

 floating variety, S. natans, Linn., found occasionally, but rarely, in deeper 

 water, has the weak stems and long floating leaves nearly of S. minimum. 



