LYTHRUM. HALORAGEjE. 217 



Hippuais. 



cesses ; petals 4, caducous ; stamens 4 ; style very short or none ; capsule 

 4-celled. On wet banks, along the Columbia River and the Eastern States. 



2 LYTHRUM Juss. Gen. 132. 



Herbs, rarely sufFrutescent plants, with opposite or scat- 

 tered entire leaves and purplish or white flowers. Calyx cj'lin- 

 drical, striate, with 4-6 short lobes and usually as many inter- 

 mediate teeth or processes. Petals 4-6. Stamens as many or 

 twice as many as petals, inserted on the tube of the calyx. 

 Style filiform: stigma capitate. Capsule oblong, 2- celled, many- 

 seeded, enclosed in the calyx-tube. 



L. adsurgens Greene Pitt, ii, 12. Stems 1- '■ feet long, from a stoloni- 

 feroug perennial base, stoutish but tough and flexible, 5-angled, decumbent 

 or nearly prostrate, herbage pallid and glabrous : leaves scattered, linear, 

 sessile : calyx 3-3 lines long the small lobes subulate, the intermediate 

 processes broad and mucronulate : petals pale purple,- but little exceeding 

 the calyx-lobes. In wet or springy places, Puget Sound to California. 



Oeder XXXVII. HALORAGE^ Endl. Gen. 1155. 



Herbs or suffruticosc' plants growing in water or wet places 

 with various leaves and small axillary sessile perfect, rarely 

 monoecious or dioicious flowers. Limb of the calyx 3-4-lobed or 

 entire, sometimes wanting. Petals 3-4 small or wanting. Sta- 

 mens as many or twice as many as the lobes of the calyx, some- 

 times fewer, inserted with the petals into the summit of the 

 calyx. Ovary coherent with the calyx, 1-4-celled, with a solitary 

 pendulous ovule in each cell. Styles 1-4 or none : stigmas as 

 many as cells of the ovary, distinct. Fruit dry and indehiscient. 

 Seeds anatropous with a straight embryo and thin fleshy albu- 

 men. 



* Stamens one. 



1. Hippnris. Ovary 2-celled : leaves verticillate, linear or oblong, entire. 



2. Callitriche. Ovary 4-celled: leaves opposite, linear or spatulate, 

 entire. 



* * Stamens 5-8. 



3. Myriophyllum. . Ovary 4-celled : leaves verticillate subvert' cillate or 

 scattered, the emersed entire toothed or pectinate, the submerged pin- 

 natifld. 



1 HIPPURIS. L. Gen. n. 11. 



Aquatic perennial herbs with simple stems, verticillate entire 

 leaves and minute axillary flowers. Flowers perfect, or by 

 abortion sometirnes neutral or pistillate. Calyx-tube adherent 

 to the ovary, the limb minute, entire. Petals none. Stamen 

 one, inserted on the margin of the calyx. Style filiform, stig- 

 matic its whole length and lying in a groove of the stamen. 

 Fruit 1-celled, 4-seeded. 



H. vulgaris L. Sp. i, 4. Stems erect, 10-20 inches high, rather stout: 

 leaves in whorls of 6-12, linear, 8-12 lines long or more, one-nerved: 



