556 PATAGONIAN EXPEDITIONS I BOTANY. 



Family 59. CALLITRICHACE^E. Water-starwort Family. 



Aquatic herbs, rarely terrestrial, with opposite, exstipulate, entire leaves, 

 and minute, perfect or monoecious, axillary flowers. Perianth none. 

 Bracts 2-none. Stamen i . Ovary 4-celled, with 2 styles. Seed i in each 

 cell, anatropus, with endosperm. Fruit 2-4-coccous. 



Only i genus, 20 species, widely distributed (except in S. Africa). 



CALLITRICHE Linn. 

 Characters of the Family. 



i. C. DEFLEXA A. Br. ( C. pedunculata A. Gray.) 



Small annual, forming tufts on moist soil, without stellate scales. 

 Leaves uniform, minute, obovate or obovate-lanceolate, crowded. Bracts 

 none. Pollen subglobose, minute. Fruit minute, broader than long, 

 dicoccous; mericarps subsinuate, convex dorsally, keels acute. Stigmas 

 patent, persisting, and often reflexed. Pedicels long or short, reflexed, or 

 spreading. 



Amer., in warm and temperate parts. Swamps in Staaten I., and in 

 Basket I. 



2. C. OBTUSANGULA LeGall. 



Upper leaves obovate, often rosulate, many-nerved ; lower remoter and 

 narrower. Pollen subglobose. Fruit handsome, rounded at the angles, 

 sulci evanescent. Stigmas persistent, erect or spreading. 



(Eur.) ; Staaten I. (var. antarctica Engelm.). 



3. C. PALUSTRIS Linn. (C. verna L.) 



Submerged leaves linear, the others obovate. Fruit sessile, oval, 2- 

 bracted, flat on the face, longer than the styles. 



(Eurasia and N. Amer., also in Kerguelen L); Falklands; Fuegia. 



4. C. VERNA Linn. (? being sterile here). 



Varies much in foliage; upper and floating leaves usually oval and 

 pediceled, 2-ribbed; lower leaves linear, i -ribbed; rarely all linear. Fruit- 

 ing pedicels short, with 2 falcate bracts at base ; fruit tetragonal, lobes 

 dorsally keeled or winged. 



(Eur. and N. Amer.) ; Chubut, in swamps and pools near Lago Fontana. 



