LYTHEACEAE. 201 



Style present, simple or compound : stigma terminal. 



Anthers opening by pores. Fam. 1. MELASTOMACEAE. 

 Anthers opening by longitudinal valves. 



Hypanthium merely enclosing the ovary. Fam. 2. LYTHKACEAB. 



Hypanthium adnate to the ovary or mainly so. Fam. 3. EPILOBIACEAE. 



Style wanting : stigmas sessile. Fam. 4. GUNNERACEAE. 



FAMILY 1. MELASTOMACEAE. MEADOW-BEAUTY FAMILY. 



Herbs, shrubs, or trees. Leaves opposite : blades with 3-several ribs. 

 Flowers perfect. Calyx of 3-6 sepals surmounting the hypanthium. 

 Corolla of 3-6 oblique petals. Androecium of 6-12 stamens, those opposite 

 the petals sometimes abortive. Gynoecium of mostly 4 united carpels. 

 Ovary enclosed in or adnate to the hypanthium. Fruit baccate or cap- 

 sular. 



1. RHEXIA L. Perennial herbs with rootstocks. Leaf-blades usually 

 3-5-ribbed. Hypanthium urceolate, prolonged beyond the ovary. Sepals 4, 

 persistent. Petals 4, deciduous. Ovary 4-celled, free. Capsule included, 4- 

 valved. DEERGRASS. 



1. R. virginica L. Stems 2-10 dm. tall: leaf -blades oblong-elliptic, oval, lan- 

 ceolate, or ovate-lanceolate, 2-10 cm. long: sepals lanceolate or triangular- 

 lanceolate : petals bright -purple, 11-17 mm. long : capsules 7-10 mm. long. S. 

 Bare, in moist sandy soil. Schists. Sum. MEADOW -BEAUTY. 



FAMILY 2. LYTHRACEAE. LOOSESTRIFE FAMILY. 



Herbs, shrubs, or tropical trees. Leaves mostly opposite: blades 

 usually entire. Flowers perfect. Calyx of 4 or 5 sepals, commonly with 

 accessory teeth. Corolla of 4 or 5 petals, or wanting. Androecium of few 

 or many stamens: anthers versatile. Gynoecium of mostly 2-6 united 

 carpels. Ovary 2-6-celled, or rarely 1-celled, free from the hypanthium. 

 Fruit a capsule, included in the hypanthium. 



Hypanthium campanulate or turbinate, becoming hemispheric or globose. 



Herbs : flowers mostly solitary in the axils : capsule septicidal : stamens 4. 



1. ROTALA. 



Shrubs : flowers in axillary cymes : capsule loculicidal : stamens 



8-10. 2. DECODON. 



Hypanthium elongate, cylindric or tubular. 



Flowers regular : hypanthium symmetrical. 3. LYTHRUM. 



Flowers irregular : hypanthium oblique. 4. PAESONSIA. 



1. ROTAIiA L. Annual leathery-succulent herbs. Leaf -blades narrow, 

 entire. Flowers usually solitary in the axils. Sepals with accessory teeth. 

 Petals usually 4. Stamens 4. Style very short. 



1. R. ramosior (L.) Koehne. Stems 0.5-4 dm. long: leaf -blades oblong to 

 linear or spatulate, 1-3 cm. long: sepals acute: petals minute: capsules 2.5- 

 3.5 mm. in diameter. Mostly on islands and shores of the Susquehanna, and 

 swamps in the southern part. Sum. 



2. DECODON J. F. Gmel. Aquatic shrubs. Leaves deciduous: blades 

 entire. Flowers in axillary peduncled cymes. Sepals 5-7, alternating with 

 small teeth. Petals 5-7. Stamens 10 or rarely 8, alternating short and long, 

 the longer exserted. Capsule loculicidally 3-6-valved. 



1. D. verticillatus (L.) Ell. Stems arching, mostly 4-16 dm. long: leaf- 

 blades lanceolate or elliptic-lanceolate, 3-20 cm. long: sepals acuminate: petals 

 purple, lanceolate to ovate, 7-9 mm. long: capsules about 5 mm. in diameter. 



