Xyris.] cxlii. xvRiDEiE (brown). 7 



1. XYBIS, Linn. ; Benth. et Hook. f. Gen. PI. iii. 842. 



Sepals 3 ; two lateral and exterior, boat-shaped, keeled ; one interior, 

 membranous, convolute or obtusely calyptriform, closely enveloping the 

 corolla when in the bud, circumscissile at the base and deciduous as 

 the corolla develops. Corolla with a slender tube and 3 spreading 

 cuneate-obovate lobes. Staminodia 3, simple, bifid or 2-armed, 

 glabrous, hairy, or divided into a brush-like tuft of hairs. Style fili- 

 form, without tubercles or processes, 3-branched above ; stigmas dilated 

 or subcapitate. — Peduncles with a basal sheath, naked above. All other 

 characters as in the Order. 



A genus of about 150 species, having the same distribution as the Order. 

 In the following descriptions, flowering bracts taken from the middle of the spike 

 are those described, unless others are specially mentioned, and their nervation is given 

 as seen by transmitted light when they are placed in water. The shape and breadth 

 of the lateral sepals is given as when seen lying on their side. In most of the species 

 the leaves and peduncles are usually more or less twisted. The ciliation or toothing 

 on the keel of the lateral sepals in some species is very minute, and, unless examined 

 under a lens of considerable power, may easily be overlooked. The dorsal area, men- 

 tioned in the descriptions, is an area on the back of the bracts in which the surface is 

 of a different character from the rest of the bract and usually appears somewhat 

 impressed, as if stamped upon it. 



Outermost bracts ^-6 in. long, unequal, spreading, much 



longer than the spike and forming a distinct involucre 1. X. foliolata. 

 Outermost bracts shorter or nearly equalling the spike, 

 adpressed, not forming a spreading involucre. 

 Bracts (or at least 2 or 3 of the outermost) with a stout 

 awn at the apex. ; plants 1-3 ft. high. 

 Bracts dull dark brown, with broad white lacerate 



and ciliate membranous margins . . .2. X. aristata. 



Bracts blackish or dark brown, shining, without 

 membranous margins. 

 Inner bracts ciliate at the apex ; lateral sepals very 

 distinctly and evenly ciliate all along the keel 

 from the base to the apex . . . . 3. X. rigidescens. 

 Inner bracts not ciliate at the apex ; lateral sepals 

 minutely ciliate along the middle part of the 

 keel or occasionally to the apex, but not on 

 the basal third . . . . . 4. A', disjtar. 



Bracts all without awns, but sometimes shortly mucro- 

 nate (see also X. dispar, in which most of the 

 bracts are without awns). 

 -•'Bracts (or at least the inner), minutely ciliolate 

 at the apex, very obtuse. 

 Keel of lateral sepals very narrowly winged, 



not ciliate ..... 22. X. aiif/usiifolia. 



Keel of lateral sepals ciliate; bracts chestnut- 

 brown. 

 Spike 2^ lin. thick ; bracts with a distinct 



greyish dorsal area . . . 29. A', conpensia. 



Spike 3-3^ lin. thick ; bracts shining 

 brown, with an obscure dorsal area 

 on some of them .... 3U. A', nit id a. 



