130 THE NAIAD FAMILY. [Schewhzcri*. 



Asia, and North America, and here and there in the mountains of central 

 Europe. In Britain, only in northern England, in Shropshire, and 

 Methuen, near Perth. Fl. summer, rather early. 



VII. TRIGLOCHIN. ARROW-GRASS. 



Tufted herbs, with linear, semi-cylindrical radical leaves, and leafless 

 flower-stems, bearing a slender raceme or spike of small greenish flowers 

 without bracts. Perianth of 6 nearly equal segments. Stamens 6. Ovary 

 and fruit of 3 or 6 1 -seeded carpels, each bearing a separate, small, 

 feathery stigma, all united at first round a central axis, but separating 

 from it when ripe. 



A small genus, chiefly maritime, but widely distributed over the globe. 



Ripe fruit linear, with 3 carpels . . . . . 1. T. palustre. 

 Ripe fruit ovoid or oblong, with 6 carpels 2. T. maritimum. 



1. T. palustre, Linn. (fig. 970). Marsh A. The tufted stock emits 

 a few slender, creeping runners. Leaves slender, but rather succulent, 

 varying from 2 to 8 inches in length, dilated and sheathing at the 

 base. Flower-stems from 6 to 12 inches high, bearing in their upper 

 half a slender spike of small, yellowish-green flowers, which are at first 

 sessile, but as the fruiting advances the pedicels lengthen to 1 or 2 lines. 

 Perianth-segments broadly ovate, the feathery stigmas just appearing 

 above them. After they fall off, the fruit lengthens to about 3 lines by 

 less than a line broad, tapering at the base ; when ripe it separates from 

 the base upwards into 3 carpels, leaving a central axis. 



In wet meadows, and marshes, and on the shallow edges of streams, 

 more especially in maritime districts, in Europe, central and Russian 

 Asia, and North America, extending from the Mediterranean to the 

 Arctic regions. Common in Britain. Fl. all summer. 



2. T. maritimum, Linn. (fig. 971). Sea A. Very near T. palustre, 

 but usually rather stouter, with more succulent leaves, the flowers nearly 

 similar ; but even in that state the ovary is broader, with 6 cells, and 

 the ripe fruit is not more than 2 lines long, more than a line broad, and 

 divides into 6 carpels. 



Generally more restricted to the vicinity of the sea than T. palustre, 

 but equally abundant with that species in the salt marshes of the 

 northern hemisphere. Common in Britain. FL from spring till autumn. 



LXXIX. ALISMACEJB. THE ALISMA FAMILY. 

 Marsh or water plants, with radical leaves and leafless flower- 

 stems. Flowers in terminal umbels, panicles, or racemes. 

 Perianth of 6 segments, either all similar, or 3 outer sepal-like 

 and 3 inner ones larger and petal-like. Stamens 6, 9, or inde- 

 finite. Ovary of 3, 6, or many carpels, either distinct from the 

 first or separable when in ripe fruit, each with 1, 2, or many 

 ovules. Seeds consisting, within the treta, of a large, straight 

 or hooked embryo without albumen. 



