LYTHRARIACEjE. 



441 



campanulate receptacle, thin and membranous, is marginally con- 

 tinuous with the six triangular valvate lobes of the calyx, glandular 

 at the summit ; in the intervals are an equal number of accessory 

 teeth, the origin of which is the same as in Salicaria, To these 

 teeth correspond an equal 



number of small obtuse Ammannia {PepUs) portula. 



very caducous petals, which 

 are sometimes entirely ab- 

 sent. Much lower, on the 

 internal surface of the re- 

 ceptacle, are inserted six 

 alternipetalous perigynous 

 stamens formed, each, of an 

 enclosed filament and a bi- 



locular, introrse, didymous anther, dehiscing by two longitudinal 

 clefts. The gynsecium is free, formed of an enclosed two-celled ovary, 

 surmounted by a short style with capitate stigmatiferous apex. In 



Ammannia {Suffrenia) filiformis. 



Fig. 418. Flower (|). 



Fig. 419. Long. sect, 

 of flower. 



-^ 



Fig. 420. Flower (f). 



Fig. 421. Diagram. Fig. 422. Long. sect, of flower. 



the internal angle of each cell is a placenta supporting an indefinite 

 number of anatropous ovules. The fruit, enclosed in the persistent 

 receptacle, is a membranous and polyspermous capsule, the seeds of 

 which contain, under their thick coats, a fleshy embryo, with oval 

 cotyledons and short radicle. In southern Russia there is a Feplis 

 called P. borysthenica,^ which differs from P. portula only in the 

 greater length of its style. A genus has been made of it under the 

 name of Middendorjffia,^ Another Peplisy in the United States, P. 

 diandra,^ type of the genus Bidijplis^^ is quite similar to our P. 



ex Spreng. Syst. ii. \Z5.—Ammania 

 borysthenica DC. Frodr. iii. 78, n. 10. 



2 Trautv. Diss, de Middendorffia, Mem. Sav. 

 etr. Ac. Petersb. iv. 489, t.4.— Walp. Rep. v. 673. 



3 NuTT. ex DC. Prodr. iii. 77, n. 4. — Ptolina 



aquatica Nutt. (ex DC). 



^ Eapin. Atlant. Journ. (1833) n. 6, p. 23.— 

 Endl. Gen. 14z7.— B. H. Gen. 777, n. 3.- 

 EyiiobricMa M. 0. Curt. Torr. et Gr. Fl. N.- 

 Atncr. i. 479. 



