Jones: Flora of Illinois, 115. Onagraceae 189 



113. Lythraceae Lindl. — Loosestrife Family 



I. Flowers regular; petals equal. 



2. Flowers small, axillary, solitary or few. 



3. Calyx-tube campanulate or hemispherical, not striate. 

 4. Petals 4; calyx-tube with appendages in the sinuses. 



5. Flowers solitary, sessile, axillary; capsules 4-loculed, septicidal I. Rotala 



5. Flowers usually more than I in each axil; capsules 2-4-loculed, irregularly 



dehiscent 2. Ammannia 



4. Petals absent; calyx-tube without appendages 3. Peplis 



3. Calyx-tube cylindrical, striate; petals 5-7, usually 6 4. LythTum 



2. Flowers large (2 cm. in diameter), in axillary clusters, trimorphous; petals usually 5; 



plants semi-shrubby 5. Decodon 



1. Flowers irregular and unsymmetrical ; petals unequal; plants glandular-pubescent.... 

 - ...6. Cuphea 



1. Rotala L. 

 R. ramosior (L.) Koehne. Wet ground, throughout 111. July-Sept. 



2. Ammannia L. 



A. cocc'mea Rottb. Muddy banks and shores, locally common throughout 

 111. July-Aug. 



3. Peplis L. — Water-purslane 



{Didiplis Raf.) 

 P. diandra Nutt. Wet ground or shallow water, rare. June-Aug. Known 

 from Cook, Hancock, Henderson, Menard, Wabash, and St. Clair counties. 

 lAmmannia nuttallii Gray; D. diandra (Nutt.) Wood} 



4. Lythrum L. — ^Loosestrife 

 L. alatum Pursh. Meadows and moist ground, common June-Aug. 



5. Decodon J. F. Gmel. — Swamp Loosestrife 



D. verticillatus (L.) Ell. Swamps, not common; known in III. from Lake, 

 Cook, Woodford, and Mason counties. 



6. Cuphea P. Br. — Waxweed 



C. petiolata (L.) Koehne. Dry soil, throughout 111., except the n.w. coun- 

 ties. July-Oct. 



114. Melastomaceae R. Br. — Melastoma Family 

 1. Rhexia L. — Meadow-beauty 

 R. virginica L. Moist sand-barrens, or in peaty soil, locally throughout III.; 

 known from Cook, Kankakee, La Salle, Mason, Cass, and Richland counties. 

 July-Sept. 



115. Onagraceae Dum. — Evening-primrose Family 



I. Flowers with 4 petals (rarely 0) ; sepals 4-6 (rarely apparently only 2) ; stamens 4-12. 

 2. Fruit a many-seeded capsule. 



3. Seeds with a tuft of silky hairs; flowers (in our species) not yellow 



I . Epilobium 



3. Seeds without hairs. 



4. Hypanthium scarcely or not at all extended beyond the ovary. 



5. Stamens 8-12, in two series _ 2. Jiissiaea 



5. Stamens 4 3. Ludmgia 



