16 TRIAND. MONOG. 



Tliis has often been confounded with the preceding species, but atten- 

 ' tion. to tl:e above cl;.aracters will reraove every difficulty. This is the 

 larger plant of tlie two ; the cauline leaves are more linear, the 

 upper ones more frequently toothed or even pectinated. Fhvjers 

 fl'3sh-coloured, not in heads but in loose corymbs, with fewer and 

 narrower bracteas. In the axil of the upper forks of the stem is 

 always a solitary flower. T\\e fruit is widely different in shape, 

 marked with five elevated ribs, and crowned with three unequal, al- 

 vAOst foliaceous teeth. 



3. IRIS. 



1. I. Pseudacorus (yellow Water -Iris), leaves ensiform, each 

 alternate segment of the beardless perianth smaller than the 

 stigma. Light/, p. 86. E. B.t. 57 S. 



Hab. Ditches and marshy places, common. F/. July. 1/. 



Flowers large, ycWow. jRoo/s large, horizontal, fleshy, very acrid. A 

 piece held between the teeth is said to cure the tooth-ache. In Ar- 

 ran they are used to dye black, and in Jura mixed with copperas, 

 to make ink. Light/. 



4. SCHCENUS. 



* Culms leafy. 



1. Sch. alhis (white -headed Bog-rush), culm triangular, leaves 

 Hneaii-setaceous, flowers terminal sub-corvmbose as long as 

 the involucrum. Light/, p. SJ . E. B. t.'9S5, 



Hab. Moors and boggy places, common. Fl. July, Aug. 11. 



Culm 6 — 8 inches high, leafy, leaves sheathing at the base. Each 

 head consists of three or four clusters of almost white Jiowers col- 

 lected into a sort of corymbus as long or longer than the involu- 

 crum, by which it is at once distinguished. Bristles eight or ten at 

 the base of the fruit. Stam. two or three. 



** Culms naked. 



2. iich. nigricans (black Bog -r 21s h), culm rounded, spikelets of 

 flowers collected into an ovate cluster, involucrum of two 

 leaves, the exterior one longer than the flowers. Light/, p, 86. 

 E.B. t. 1121. 



Hab. Moors and boggy places, common. FZ. June, July. l/. 



Culms about a foot in height, the base sheathed with the black rem- 

 nants of the former year's leaves. Leaves setaceous, rigid, gene- 

 rally shorter than the culms. Spikelets several, dark, shining, pur- 

 plish-brown, almost black at the base of the glumes. Leaflets of 

 the involucrum subulate, dilated at the base and dark-brown, the 

 upper part greenish, one much shorter, the other generally much 

 longer than the flower. 



3. Sch. compressus (compressed Bog-rush), culm roundish, spike 

 distichous shorter than the single involucrum, spikelets many- 

 flowered, leaves plane. Light/, p. 87. E.B. i.791. (Scirpiis 

 Car ids. IVilld. ct Host. Carcx uliginosa. L. 



Hab. Bogs, rare. By the side of lochs la Hay, Ugh/. Dumbarton 



