118 ENGLISH BOTANr 



ORDER LXIX.— CALLITRICHACEiE. 



Small sliglitly branched herbs, growing in water or on mud. Stems 

 slender, brittle, rooting at the nodes. Leaves opposite, sliglitly connate, 

 entire or rarely lobed, generally notched at the apex. Flowers monoe- 

 cious or rarely perfect, sessile, axillary, solitary, very minute, usually 

 bructiate, but the bracts sometimes caducous. Perianth none. Stamens 

 in the male flowers 1 ; filament elongate ; anther 2-celled. Female 

 flowers with a 4-lobed ovary ; styles 2, filiform, stigmatiferous through- 

 out. Fruit sessile or stalked, suborbicular, much compressed, 4-lobed 

 and 4-celled, the lobes in pairs, with an impressed line on each face 

 indicating the separation between the two pairs, each pair with a more 

 or less deep furrow between the 2 lobes of which the pair is com- 

 posed, at length usually splitting into 4 indehiscent cocca. Seeds 

 4, 1 in each cell of the fruit, pendulous, with a small caruncule at the 

 apex ; albumen fleshy ; embryo central, straight. 



In some of the species flowers with stamens and pistil together 

 have been found, so that its position next Euphorbiaceas is perhaps 

 unnatural. 



(?^i\^^7^/.— CALLITRIOHE. Linn. 



The only known genus of the order. 



The name of this genus of plants is derived from two Greek words, /coXoc (Jcalos'), 

 beautiful, and 6pi^ {thrix), the hair, 



SPECIES I.-CALLITRICHE VERNA. Linn. 



Plates MCCLXXI. to MCCLXXIV. 



Leaves linear or oblanceolate or obovate, none of them enlarged at 

 the base, more or less notched at the apex, otherwise entire. Anthers 

 rising out of the water immediately before fertilisation takes place; 

 pollen grains with 2 coats. Marginal furrows of the fruit shallow, not 

 extending nearly to the bottom of the lobes. Stem and leaves furnished 

 with stellate scales. Submerged leaves commonly translucent and 

 1-ncrved, the upper ones generally floating and in a rosette; those 

 exposed to the air opaque, furnished with stomata, and often 3-nerved. 



