XYRIDACEuE. (YELLOW-EYED GRASS FAMILY.) 487 



Order 181. XYIUDACEiE. (Yellow-eyed Grass Fam.) 



Rush-like herbs, with equitant leaves sheathing the base of a naked scape, 

 which is terminated by a head of perfect 3-androus fotvers, with extrorse an- 

 thers, a ylumaceous calyx, and a regular corolla; the B-valved mostly \-celled 

 pod containing several or many orthotropous seeds with a minute embryo eit 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. MAYACA, Aublet. (Svena, 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 1-celled with 3 parietal few-ovulcd placentas : style hliform : 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. HI. Miclmuxii, Schott & Endl. Peduncles not much exceeding the 

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

 ginia, and southward. July. 



2. XYRIS, L. Yellow-eyed Grass. 



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-hearing 

 at their apex. Style 3-cleft. Pod oblong, free, 1-celled with 3 parietal more or 

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

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



1. X. I>5i!!»o$:a, 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-ovoid 

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

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

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

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

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

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



2. X. Carolinif&saa, "Walt. Scape flattish, 1-angled below, 2-edgcd at 

 the summit, smooth ; leaves linear-sword-shaped, flat ; head globular-ovoid (,V 



