XYRIDACE^E. (YELLOW-EYED GRASS FAMILY.) 487 



ORDER 131. XYJRIDACEJE. (YELLOW-EYED GRASS FAM.) 



Rush-like herbs, with equitant leaves sheathing the lase of a ndkea scape, 

 which is terminated by a head of perfect 3-androus flowers, with extrwse an- 

 thers, a glumaceous calyx, and a regular corolla; the 3-valved mostly l-celled 

 pod containing several or many ortholropous seeds with a minute embryo at the 

 apex of fleshy albumen: represented by Xyris. The anomalous genus 

 Mayaca, consisting of a few moss-like aquatic plants, intermediate in char- 

 acter between this family and the last, may be introduced here. 



1. UIAYACA, Aublefc (SYENA, Schreber.) 



Flowers single, terminating a naked peduncle. Perianth persistent, of 3 her- 

 baceous lanceolate sepals and 3 obovate petals. Stamens 3, alternate with the 

 petals. Ovary l-celled with 3 parietal few-ovuled placenta : style filiform : stig- 

 ma simple. Pod 3-valved, several-seeded. Moss-like low herbs, creeping in 

 shallow water, densely leafy; the leaves narrowly linear, sessile, 1 -nerved, pellu- 

 cid, entire, notched at the apex : the peduncle solitary, sheathed at the base. 

 (An aboriginal name.) 



1. M. Michauxii, Schott & Endl. Peduncles not much exceeding the 

 leaves, nodding in fruit; petals white. (Syena fluviatilis, Pursh.) S. E. Vir- 

 ginia, and southward. July. 



2. X "tltlS, L. YELLOW-EYED GBASS. 



Flowers single in the axils of coriaceous scale-like bracts, which are densely 

 imbricated in a head. Sepals 3 ; the 2 lateral glume-like, boat-shaped or keeled 

 and persistent; the anterior one larger and membranaceous, enwrapping the 

 corolla in the bud and deciduous with it. Petals 3, with claws, which cohere 

 more or less. Fertile stamens 3, with linear anthers, inserted on the claws of 

 the petals, alternating with 3 sterile filaments which are cleft and plume-bearing 

 at their apex. Style 3-cleft. Pod oblong, free, l-celled with 3 parietal more or 

 less projecting placentae, 3-valved, many-seeded. Flowers yellow. (Svpis. 

 an ancient name of some plant with 2-edged leaves, from vpov, a razor.) 



1. X. lmlt>6sa, Kunth. Scape slender, from a more or less bulbous base, 

 somewhat 3-angled, flattish at the summit, very smooth, much longer than the 

 narrowly linear leaves, both commonly twisted with age ; head roundish-ovc/ 

 (4" - 5" long) ; lateral sepals oblong-lanceolate, finely ciliate-scabrous on the nctf 

 wingless keel, and usually with a minute bearded tuft at the very apex. (X. ,; 

 pacai, Michx. in part. X. Indica, Pursh. X. flexuosa, Muhl. Cat. X. brevt 

 folia, of Northern authors, not of Michx.} Sandy or peaty bogs, from New 

 Hampshire and Michigan southward : rare except near the coast. July -Sept 

 Leaves l'-8', the scape 3' -14', high. Petals minutely toothed at the sum- 

 mit. This species should have borne Mulilenberg's name of X. flexuosa, which, 

 however, Elliott appears to have applied rather to the following. 



2. X. Caroliniaua, Walt. Scape flattish, 1 -angled below, 2-edged at 

 the summit, smooth; leaves linear-sword-shaped, flat; head globular-ovoid (5'* 



