HIPPURIS.] HALORAGE^E. 141 



goose-quill or less ; rarely floating flaccid and flowerless. Leaves ^-li in., 

 close-set, tips withered. Flowers green, sessile. Anthers red. Erupt 

 minute, smooth, green. DISTRIB. Of the genus. 



2. MYRIOPHYL'LTJM, L. WATER MlLFOIL. 



Glabrous marsh or aquatic herbs ; branches often floating. Leaves 

 opposite alternate or whoiied. Flowers small, axillary, solitary or spiked ; 

 upper male, lower female, intermediate often 2-sexual. MALE fl. Calyx 

 4- 'rarely 2-lobed or 0. Petals 2 or 4, concave. Stamens 2, 4, or 8 ; 

 anthers long, basifixed, bursting laterally. FEM. fl. Calyx-tube 4-grooved; 

 lobes 4, minute or 0. Petals minute or 0. Ovary 4- rarely 2-celled. 

 Styles 4, very short, plumose ; drupes 4. Seeds oblong ; albumen copious. 

 DISTRIB. Ubiquitous ; species 15. ETYM. pvpios and $v\\ov, from 

 the finely-divided leaves. 



1. M. verticilla'tum, L. ; spike erect in bud, floral leaves all whorled 

 in about fives pinnatifid or pectinate all longer than the flowers, upper 

 axils usually flowerless. 



Ditches and ponds, from Northumberland southwards, and in Ireland ; rare ; 

 fl. July-Aug. Rootstock creeping. Stems floating, leafy. Leaves 1-2 in., in 

 close-set whorls ; segments distant, capillary, collapsing when removed from 

 the water. Spike elongate. Flowers white. Antlers linear. Fruit sub- 

 globose, green, rounded on the back. DISTRIB. Europe, N. Africa, Siberia 

 to Dahuria, W. Asia to India, E. and W. N. America. 



VAR. pectina'tttm, DC. (sp.) ; floral leaves hardly longer than the flowers. 



2. M. alterniflo'rum, DC.; spike curved at the tip in bud, female floral 

 leaves whorled in threes or fours pectinate longer than the flowers, male 

 opposite or alternate entire or serrate shorter than the flowers. 



Ponds and ditches ; ascending to 1,200 ft. in the Highlands ; fl. June-Aug. 

 Habit of M. spicatum, L. ; but more slender and flowers fewer, and in- 

 habits lakes in hilly and upland districts. DISTRIB. Europe (Arctic), N. 

 Africa, Arctic America. 



3. M. spica'tum, L. ; spike erect in bud, floral leaves all whorled in 

 about fours pectinate shorter than the flowers. 



Ponds and ditches, ascending to 1,200 ft. in the Highlands ; fl. June-Aug. The 

 small floral leaves, giving the inflorescence a more spicate appearance than 

 M. verticMatiim, is its best character ; the fruit also is less globose. DISTRIB. 

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



3. CALLIT'RICHE, L. WATER STAR-WORT. 



Slender glabrous marsh or aquatic plants. Leaves opposite, quite entire, 

 upper often rosulate. Flowers monuecious, minute, solitary, axillary. 

 MALE fl. Stamen 1, subtended by two bracts, filaments slender; anther-cells 

 confluent above. FEMALE fl. Bracts 2 or 0. Ovary sessile or shortly 

 peduncled, 4-lobed longitudinally, 4-celled ; styles 2, slender, stigmatose all 

 over. Fruit compressed, indehiscent, 4-lobed, 4-celled, lobes margined or 

 winged at the back, at length separating. DISTRIB. Chiefly temp, waters ; 

 species 3 or 4. ETYM. na-Xtis and Opll-, from the elegance of its capillrn-n 

 ramification. I have followed Hegelmaier's limitation of the British forms 

 of this very variable genus. Its alBuities are doubtful. 



