558 CALLITRICHACEJE. WATER STAR-WORT TRIBE. 



ORD. LXXYII. CALLITEICHACE^. WATER 

 STAR-WORT TRIBE. 



Flowers in different parts of the same plant, axillary, 

 solitary, very minute, imperfect, with two white bracts 

 at the base ; calyx and corolla absent ; barren flower -, 

 with one stamen, or very rarely two ; filament thread- 

 like, bearing a 1 -celled anther, which opens at the 

 summit by two transverse valves ; fertile flower, 

 ovary 4-angled, 4-celled ; styles 2, awl-shaped ; stigma 

 simple ; fruit 4-celled, 4-lobed, 4-seeded, flattened late- 

 rally, not opening. Small aquatic, herbaceous plants, 

 with long, weak, tangled stems, which are usually sub- 

 merged, opposite simple entire leaves, of which the 

 upper alone float on the surface of the water, and long 

 thread-like silvery roots, which proceed from the joints 

 of the stem, and are either attached to the soil below 

 or are suspended in the water. 



1. CALLITRICHE (Water Star-wort). Characters given 

 above. 



1. CALLITRICH (Water Star-wort). 



1. 0. verna (Vernal Water Star-wort). Leaves in 

 pairs, united at the base ; flowers in the axils of the 

 leaves ; carpels bluntly keeled at the back. Streams 

 and stagnant water ; everywhere. An aquatic plant 

 with long slender stems, which send out shining roots 

 from the joints ; either growing in running water, when 

 the leaves are usually very narrow, or in stagnant water, 

 when the upper leaves are broader, and float on the sur- 

 face, crowded into a starry form, the stamens being the 

 only parts of the plant actually raised above it. Fl. 

 May July. Annual. 



2. C. autumndlis (Autumnal Water Star- wort). 

 Carpels winged at the back. Resembling the last, and 

 growing in similar situations ; but rare. In this species 

 the whole plant is submerged, all the leaves are narrow 

 and abrupt, and of a deeper green. Fl. June October. 

 Annual. 



