279 ACORUS CALAMUS 



tinned by a tapering two-edged bract (spathe), 2 3 feet long, in 

 all respects like the leaves. Perianth polyphyllous, of 6 leaves 

 imbricated in two rows, erect, oblong-obovate, acute, scarious, 

 thicker at the top and bent inward, one-nerved, whitish, incon- 

 spicuous and soon withering. Stamens 6, opposite to and as 

 long as the perianth leaves, either free or very slightly united 

 with their bases, filaments membranous, flattened, slightly tapering 

 upwards, with a dark nerve up the centre, anthers small, readily 

 detached, 2 -celled, cells divergent at the base. Ovary large, 

 exceeding the perianth and stamens, obo void-top- shaped, trigonous 

 but irregularly so from pressure of adjacent flowers, smooth, 

 grooved along the angles, the exposed portion thick, pale green, 

 bluntly pointed, the summit capped by the minute sessile stigmas, 

 the lower portion thin and white, 3-celled, the lower part of the 

 cells excavated in the substance of the spadix, filled with a brittle 

 gelatinous substance in which the ovules are immersed; ovules 

 very minute, 5 or 6 in each cell, forming tufts which are pen- 

 dulous from the large placentas projecting from the upper part of 

 the axis, and are surrounded at the base by a tuft of very fine 

 hairs ; coats of the ovule very distinct though extremely delicate 

 and transparent, their mouths prolonged into tubes with a fringe 

 at the orifice, the inner one protruded much beyond the outer, 

 nucleus small, dark, club-shaped. Fruit (not seen) bluntly six- 

 sided, prismatical-clavate, about f inch in diameter in the thickest 

 portion, herbaceous, indehiscent, 1 3 seeded. Seed with a thin 

 testa, embryo in the axis of the horny endosperm, green, cylin- 

 drical, radicle next the hilum. 



Habitat. Though at the present day common throughout the 

 continent of Europe, there is little doubt that the Sweet Flag is 

 indigenous to more eastern countries. So far as Central and 

 Western Europe is concerned it appears to have been almost 

 certainly spread by means of botanic gardens since the end of the 

 sixteenth century. Clusius first cultivated it at Vienna in 1574 

 from a root received from Asia Minor, and distributed it to other 

 botanists in Belgium, Germany, and France. As is the case with 

 other rhizomatous aquatics it is very readily propagated, and it 



