826 LYTHRACEAE 



the axils. Hypanthium campanulate, often becoming globular, 4-angled. Sepals 4, often 

 accompanied by small teeth in the sinuses. Petals 4, mostly early deciduous. Stamens 4-8 : 

 filaments filiform, sometimes short. Ovary subglobose, commonly 2-4-celled, enclosed in 

 the hypanthium : style filiform, sometimes short : stigma capitate. Capsule membranous, 

 subglobose, opening irregularly. Seeds angular, minute. Testa coriaceous. Embryo with 

 broad auricled cotyledons. 



Flowers or capsules sessile or nearly so. 



Leaves broadest above the middle : capsules 5-6 mm. in diameter. 1. A. Koehnei. 



Leaves broadest below the middle : capsules 3-4 mm. in diameter. 2. A. coccinea. 



Flowers or capsules in long-peduncled cymes. 3. A. auriculata. 



1. Ammannia Koehnei Britton. Stems stout, glabrous, 1-6 dm. tall, simple or 

 branched below or throughout : leaf-blades spatulate, oblanceolate or oblong, 2-8 cm. long, 

 obtuse, entire, the lower ones sessile, the upper partially clasping by the auricled bases : 

 flowers sessile, 1-3 in an axil : hypanthium campanulate, becoming globular : sepals acute : 

 petals white or pink, spatulate, often fugacious : stamens and short style included : capsules 

 subglobose, 5-6 mm. in diameter. [A. latifolia Chapm., not L.] 



In swamps and along streams, New Jersey to Florida. Summer and fall.) 



2. Ammannia coccinea Rottb. Stems stoutish, glabrous, 1-5 dm. tall, simple or 

 branched below : leaf-blades linear or linear-lanceolate, 2-6 cm. long, acute or acuminate 

 at the apex, entire, dilated at the cordate obtusely auricled base, sessile : flowers 1-5 in an 

 axil, sessile or on peduncles much shorter than the calyx : hypanthium campanulate and 

 somewhat angled when young : sepals acute : petals broadly obovate, obtuse, purple or 

 pink : stamens and slender style exserted : capsules subglobose, 34 mm. in diameter : seeds 

 0.5-0.7 mm. long. 



In swamp and low places, Iowa to Indiana, Kansas, Florida and Texas, and through Mexico and 

 Central America to Brazil. Summer and fall. 



3. Ammannia auriculata Willd. Stems rather slender, glabrous, 0.5-2.5 dm. tall, 

 simple or finally widely branching : leaf-blades oblong to linear-lanceolate, 1-3 cm. long, 

 acute or acutish, entire, sessile, more or less clasping by the auricled bases : flowers small, 

 in axillary peduncled cymes, or rarely solitary on peduncles 5-10 mm. long : hypanthium 

 campanulate, becoming subglobose : sepals acute : petals white or pink, broadly spatulate : 

 stamens and slender style exserted : capsules subglobose, 2-2.5 mm. in diameter : seeds 0.4 

 mm. in diameter. 



About ponds and swamps, Nebraska to Texas, New Mexico and through Central America to Brazil. 

 Spring and summer. 



3. ROTALA L. 



Annual or biennial swamp-inhabiting herbs. Stems 4-angled. Leaves opposite : blades 

 narrow, entire. Flowers inconspicuous, usually solitary in the axils. Hypanthium campan- 

 ulate becoming subglobose. Sepals very small. Petals usually 4. Stamens 4 : filaments 

 short : anthers 2-celled. Ovary subglobose, 4-celled, free : style very short : stigma entire or 

 nearly so. Capsules 4-celled, subglobose, septicidally 4-valved, the valves transversely 

 triate. Seeds minute. 



1. Rotala ramosior (L.) Koehne. Stems erect or ascending from a decumbent base, 

 0.5-4 dm. long, glabrous : leaf -blades oblong to linear or spatulate, 1-3 cm. long, obtuse or 

 acutish, entire, narrowed at the base, sessile or short-petioled : flowers inconspicuous, 1, or 

 rarely 3 together, sessile or nearly sessile in the axils : hypanthium becoming subglobose, 

 2.5-3.5 mm. in diameter: sepals acute: petals very small, white: style almost wanting: 

 capsules subglobose, 2.5-3.5 mm. in diameter. 



In swamps, about ditches and in wet sand, Massachusetts to Nebraska, Florida, Texas and Mex- 

 ico. Also on the Pacific slope and in South America. Summer and fall. 



4. HEIMIA Link & Otto. 



Low spreading shrubby herbs, with elongated branches. Leaves opposite or whorled : 

 blades narrow, entire. Flowers solitary on axillary peduncles which are shorter than the 

 flowers, bearing 2 scales. Hypanthium hemispheric-campanulate. Sepals 6, erect, alter- 

 nating with spreading teeth at the sinuses. Petals 6, spreading, usually about as broad as 

 long. Stamens 12, about uniform : filaments slender. Ovary sessile, 4-celled : style elon- 

 gated. Capsule 4-celled. Seeds minute, wingless. 



1. Heirnia salicifolia (H.B.K.) Link & Otto. A bright green glabrous herb, 

 0.5-2 m. tall, with much-branched stems : leaf-blades narrowly oblong or oblong-lanceolate, 



