XYRIDACE.E. (yELLOW-F.YED GRASS FAMILY.) 527 



§ 1. Sheath of the scape longer than the leaves. Biennials? 



1. X. brevifolia, Michx. Scape uearly terete, smooth ; leaves Larrowly 

 linear, smooth ou the edges ; spike globose, light browu, few-flowered ; bracts 

 soon lacerated at the apex ; lateral sepals lanceolate, rigid, creuulate ou the 

 wingless keel ; petals obovate, rounded ; sterile filaments sparingly bearded. 



— Low sandy pine barrens, Florida to North Carolina. April- May. — Plant 

 light brown. Scape 6'- 12' high, clustered. Leaves l'-3' long. Spike 2"- 

 3" long. Petals 2" long. 



2. X. flabelliformis, Chapm. Scape filiform, smooth, terete below, 

 slightly coni])ressed above ; leaves very short, linear-lanceolate, smooth, spread- 

 ing like a fan, laterally curved ; spikes oblong, mostly acute, few-flowered, 

 angular; bracts light brown, entire ; lateral sepals lanceolate, short-fringed on 

 the wingless keel ; petals obovate; sterile filaments often beardless. — Low 

 pine barrens, near the coast. West Florida. April -May. — Scape 4' - 12' 

 high. Leaves I'- 1' long. Spikes 2" -4" long. Petals 2" long. 



§ 2. Sheath of the scape shorter than the leaves. Perennials. 



* Sterile filaments bearded: sepals included. 



-I- Lateral sepals fringed on the keel. 



3. X. ambigua, Beyr. Scape rigid, finely furrowed, rough, 2-edged 

 above, 1-angled below; leaves lineai'-lanceolate, rough on the edges; spike 

 ovate-lanceolate or oblong, even, often acute, many-flowered ; bracts light 

 brown, oval, not crowded ou the spike ; lateral sepals lanceolate, tapering at 

 each end, shining, narrowly winged; petals round-obovate ; seeds ovoid. — 

 Open grassy pine barrens, Florida to North Carolina. July - Sept. — Scape 

 2°-3"' high, mostly solitary. Leaves 6'- 12' long. Spikes 9"- 15" long. 

 Petals k' long. 



4. X. striata, Chapm. Scape flattened and broaiUy margined, rough- 

 edged above, smooth and 1 - 2-angled below, slightly striate ; leaves long, 

 linear, .smooth ; spikes oblong or cylindrical, obtuse, many-flowered ; bracts 

 dark brown, orbicular, crowded on the spike ; lateral sepals broadly winged 

 above the middle, narrowed below; petals small, wedge-obovate ; seeds ovoid. 



— Shallow ponds in the pine barrens. West Florida. July -Sept. — Scapes 

 slender, clustered, 2° -3° high. Leaves l°-H°loug. Spikes 9"- 12" long. 

 Petals 2" long. 



5. X. flexuosa, Muhl. Somewhat bulbous ; scape smooth, 2-edged 

 above, nearly terete below; leaves linear, smooth; spikes globose, few- 

 flowered ; lateral .«epals lanceolate, wingless. (X. bulbosa, Knufh.) — Swamps 

 in the upper districts of Georgia, and northward. Julv-Sept. — Scape 6'- 

 12' high. Leaves 4' -8' long. iSpike 3"-5" long. 



-I- ■<- Lateral sepals broadlij winged, and cariouslij toothed or fimbriate. 



6. X. Elliottii, Chapm. Scape slender, flattened and 2-edged through- 

 out, or 1 -edged below, roughish and mostly spiral; leaves narrowly linear, 

 sharp edged, twisted; spike few-flowered, elliptical, obtuse; lateral sepals 

 linear, the wing cut-toothed above the middle; petals obovate. (X. brevi- 

 folia, Ell. ex descr. ) — Wet grassy pine barrens, Florida to South Carolina. 

 July. — Scape \°-\\° high. Leaves 6'- 9' long. Petals 3" long. 



