CALLITRICIIF,.] HALORAGEJ3. 153 



incurved. Filaments very slender. Furrow on the carpels shallow, not 



extending to the base of the lobes. DISTRIB. All temp, and cold climates 



(Arctic). 

 C. VERNA proper ; fruit sessile, carpels turgid sharply keeled sinus shallow, 



styles erect or spreading, pollen ellipsoid. C. verna'lis, Kuetz. ; C. aqua'tica, 



Sm. 

 Sub-sp. C. PLATYCAR'PA, Kuetz. ; fruit subsessile, carpels large flattish sharply 



keeled sinus deep, styles at length reflexed persistent, pollen subglobose. 



C. stagnalis. Scop., is a terrestrial form. Ascends to 1,500 ft. in Derby. 

 Sub-sp. C. HAMULA'TA, Kuetz. ; fruit subsessile, carpels flattish shortly broadly 



keeled sinus shallow, styles long at length reflexed deciduous, pollen 



subglobose. 



Sub-sp. C. OBTUSAN'GULA, Leg. ; leaves obovate, fruit subsessile, styles spread- 

 ing, carpels turgid obtusely trigonous at the back. C. Lachii, Warren MSS., 



has almost linear upper leaves and longer styles ; it is intermediate between 



obtusan'yula and hamula'ta (Warren). 

 Sub-sp. C. PEDUNCULA'TA, DC. ; leaves always linear, fruit peduncled or 



sessile, carpels flattish shortly sharply keeled, styles long at length reflexed 



deciduous, pollen subglobose. Flowers earlier. 



2. C. autumna'lis, L. ; leaves all submerged dilated at the base, bracts 

 0, carpels keeled or winged connate towards the axis only. 



Lakes, rare and local, Orkneys to Devon ; Ireland ; fl. June-Oct. Stem 

 brittle and leaves without stellate hairs. Leaves J-| in., all linear, trun- 

 cate, dark green. Fruit much larger than in C. ver'na. DISTRIB. N. and 

 Mid. Europe (Arctic), Siberia, N. America. 



C. autumna'lis proper ; fruit nearly sessile, winged. VAR. C. truncata, Guss. 

 fruit shortly pedicelled, keeled. 



ORDER XXXI. LYTHRA'RIE2E. 



Herbs, shrubs (or trees), branches usually 4-angled. Leaves opposite or 

 whorled, quite entire, exstipulate. Floivers regular or irregular. Calyx 

 inferior, tubular or campanulate, persistent ; lobes 3-6, valvate in bud, 

 alternating with as many teeth. Petals 3-6 rarely 0, inserted in the 

 calyx- tube, crumpled in bud. Stamens usually definite, inserted in 

 the calyx-tube, equal or unequal, inflexed in bud ; anthers versatile, 

 often recurved. Disk annular, unilateral, or 0. Ovary 2-6-celled ; 

 style straight or flexuous, stigma capitate ; ovules many, on the inner 

 angles of the cells, anatropous, horizontal or erect. Capsule enclosed in 

 the calyx-tube, 2-6-celled, or 1-celled by the septa vanishing ; placentas 

 usually forming a central seed-bearing column. Seeds various, albumen 

 scanty or ; cotyledons oblong or orbicular, 2-auricled. DISTRIB. Chiefly 

 trop. ; genera 30 ; species 250. AFFINITIES. With Onagrariece, Myr- 

 tacece, and Haloragece PROPERTIES. Astringent, acrid, and vesicatory. 

 Pomegranate bark is astringent. 



Calyx tubular. Petals exceeding the calyx-teeth 1, Ly thrum. 



Calyx campanulate. Petals minute or 2. Peplis. 



