262 XYRIDACEAE (YELLOW-EYED GRASS FAMILY) 



a corolla). Stigmas 3, two-cleft. Scape slender, bearing a single head, 2-3- 

 angled, hairy. (Name from Xd^ws, wool, and KO.V\&S, stalk.) 



1. L. anceps (Walt.) Morong. Leaves linear-awl-shaped, tufted, villous 

 (L. Michauxii Kunth.) Low pine-barrens, Va. to Fla. and Tex. 



XYRIDACEAE (YELLOW-EYED GRASS FAMILY) 



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

 is terminated by a head of perfect 3-androus flowers, with estrnrse anthers, glu- 

 maceous calyx, and a regular colored corolla ; the 3-valved mostly l-celled cap- 

 sule containing several or many orthotropous seeds with a minute embryo at the 

 apex of fleshy albumen. 



I. XYRIS [Gronov.] 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 boat-shaped and persistent ; the 

 anterior one larger, enwrapping the corolla in the bud and deciduous with it. 

 Petals 3, yellow (rarely white), with claws, which cohere more or less. Fertile 

 stamens 3, inserted on the claws of the petals, alternating with 3 sterile filaments, 

 which are cleft and in our species plumose or bearded at the apex. Style 3-cleft. 

 Capsule oblong, free, l-celled, with 3 parietal more or less projecting placentae, 

 3-valved, many-seeded. Ours apparently all perennials. (Svpis, a name of 

 some plant with 2-edged leaves, from i-vp6v, a razor.) 



Lateral sepals about equaling the subtending bracts and concealed by them. 

 Base not bulbous ; keel of the lateral sepals with an erose wing. 

 Heads ovoid. 

 Leaf-blades strictly linear or broadest at the base ; scape narrowly 2- 



margined. 

 Heads narrowly ovoid ; flower-bearing scales few (4-7) at length dark 



brown 1. X. montana. 



Heads broadly ovoid ; flower-bearing scales usually numerous, greenish 



or pale brown 2. X. caroiiniana, 



Leaf-blades broadest in the middle ; scape much flattened, conspicuously 



2- winged 8. X difformit. 



Heads ellipsoidal or subcylindric (southern) 4. X. elata. 



Base bulbous; keel of the lateral 'sepals ciliolate 5. X.Jltxuoa. 



Lateral sepals evident, much exceeding the subtending bracts or exserted 

 laterally. 



Keel of the lateral sepals slightly lacerate or erose 6. X. SmalUana. 



Keel of the lateral sepals conspicuously fringed. 



Base neither bulbous nor indurated 7. X.Jimbriata. 



Base bulbous and indurated, dark brown 8. X. arenicola. 



1. X. montana Ries. Dwarf and very slender, l-(rarely)3 dm. high, some- 

 what caespitose from a more or less branching rootstock ; leaves narrowly linear, 

 rarely more than 4 cm. long, about one fourth or one third 

 the length of the nearly filiform stipes ; heads at maturity 

 4-6 mm. thick ; seeds subcylindric-spindle-shaped. regularly 

 ribbed. (X. flexuosa, var. pttsilla Gray.) Chiefly in peat 

 bogs, Nfd. to Mt. Desert, Me., the uplands of 

 N. Y., and e. Pa. ; also on L. Superior. FIG. 

 661. 



2. X. caroiiniana Walt. Varying much 



s Id 33 X in size ; leaves g 88 - 1 ^ mostly 6-20 cm. 

 long, one third to two thirds as long as the 

 slightly ancipital stipe ; roots a tuft of delicate fibers ; root- 

 stock apparently not developed ; fruiting heads 8-10 mm. in 56->. x. caroiiniana. 

 diameter ; seeds ovoid-spindle-shaped somewhat irregularly lateral sepal x 8%. 

 about 13-ribbed, when ripe claret-colored. Wet sandy shores s ' ej *** 

 of lakes and pools, centr. Me. to Ind., and southw. FIG. 562. 



3. X. difformis Chapm. Rather stout ; leaves lance-linear, 7-12 mm. broaa 

 in the middle, thick is h ; scape strongly flattened, conspicuously 2-winged, 2-3 



