290 American Midland Naturalist Monograph No. 7 



2. One petal white, smaller; leaf-sheaths ciliate with short 



whitish hairs; leaves linear-lanceolate to lanceolate; sandy 

 soil in the western and noithcrn parts of the state. July- 

 Sept. ...-. ...C. erect a L. 



1. Margins of the spathe not united; stems decumbent, rooting at 

 the lower nodes; species nat. from Asia. 



3. All three petals blue; anthers 5; capsules 3-loculed, 5-seeded; 



seeds 2-3 mm long, reticulate; plants perennial; moist ground, 

 locally in s. 111., oiten as a cornfield weed; a widespread 



species of trop. and subtrop. regions C. diffusa Burm.f. 



3. One petal white, smaller; anthers 6; capsules 2-loculed, 4- 

 seecled ; seeds 3.5-4 mm long, gray, rugose; plants annual; 



moist shaded ground, common. June-Oct. Dayflower 



- -- - - -- C. communis L. 



1!>4. Pontederiaceae Dumort. — Pickerelweed Family 

 1. Flowers 2-lipped ; stamens 6; leaves large, cordate to lanceolate; fruit a 1- 



seeded utricle 1. Pontederia 



1. Flowers regular, salverforni; stamens 3; leaves either reniform or linear; 



fruit a many-seeded capsule 2. Heteranthera 



1 . Pontederia L. — Pickerelweed 

 P. cordata L. Margins of ponds and streams, local. June-Sept. 



2. Heteranthera Ruiz & Pavon 

 1. Leaves linear, grass-like; flowers yellow; stamens ecjual; shallow 

 water or muddy shores in the northern half of the state. July- 

 Sept. Water star-grass H. dubia (Jacq.) MacM. 



1. Leaves not linear; flowers blue or white; stamens unequal. 



2. Leaves reniform; flowers white or pale blue; spathe 3- to 6- 

 flowered ; style pubescent; shallow water or muddy shores in 



s. 111. Aug. -Sept - H. reniformis Ruiz & Pavon 



2. Leaves oval to lanceolate; flowers blue; spathe 1 -flowered; 

 style glabrous; ponds and sloughs; St. Clair Co., Egbert; 

 G. D.' Fuller '' H. limosa (Sw.VWilld. 



135. Amaryllidaceae Lindl. — Amaryllis Family 



1 . Bulbous herbs. 



2. Flowers solitary or several, the tubular or annular corona separate from 

 the filaments; stamens included 1. Narcissus 



2. Flowers umbellate, subtended by long bracts, the membranous corona 



formed by the expanded filaments; stamens long-cxserted 



2. Hymenocallis 



1. Plants not bulbous. 



3. Flowers in a long spike or spike-like raceme; lca\es basal. 



4. Perianth greenish-yellow; leaves thick, succulent; anthers versatile 



3. Agave 



4. Perianth white (in our species) ; leaves thin, flat, lanceolate; anthers 



not versatile 4. Aletris 



