378 PATAGONIAN EXPEDITIONS : BOTANY. 



(Old and New Worlds); N. Patagon., by Rio Negro. 



2. TETRAGONIA Linn. 



Herbs or undershrubs, with thickish, alternate, entire, exstipulate leaves, 

 and green to yellow or red, apetalous, axillary flowers. Calyx-tzibe ad- 

 nate to the ovary, bearing i-more stamens. Ovary mostly 3-8-celled, 

 with as many subulate styles and ovules. Fridt a winged or horned nut 

 or drupe. Seeds subreniform. 



Species 20, S. Afr., Orient, Austral, and S. Amer. 



T. EXPANSA Murr. New Zealand Spinach. 



Annual, with petiolate, ovate-rhomboid leaves and sessile flowers. 

 Stamens in fascicles of 4-5, at each sinus of the calyx. Fruit obovoid, 

 4-horned, 6-8-seeded. Fig. in Eng. & Prantl, iii, \b, p. 45. 



(Japan; Australasia; New Zealand; Extratrop. S. Am. and cult); W. 

 Patagon. 



(T. ameghinoi Speg. is Halophytmn, supra p. 372.) 



Family 36. PORTULACACE.E. Purslane Family. 



Herbs, rarely somewhat woody, generally fleshy, with regular, perfect, 

 unsymmetrical flowers. Sepals usually 2, only rarely 5. Petals 4-5 or 

 more, hypogynous. Stamens hypogynous, as many as the petals or fewer, 

 rarely more. Ovary i -celled, mostly superior ; style 2-3-parted. Cafisu!e 

 circumscissile, or opening by 3 valves. Embryo curved. 



Species 125, in tropical and subtropical countries; less abundant in 

 colder parts. Claytonia, found in Siberia and N. Amer. and in mountains 

 of Mex. and Cuba, is not found farther south in Amer. ; but C. australasica 

 Hook, is in Austral, and N. Zeal. Calandrinia, with 15 species in 

 Australia, has 60 species in the American Cordilleras from California to 



Patagonia. 



KEY TO THE GENERA. 



(All these are bisepalous except Montia.) 

 A. Ovary superior. 



b. Leaves alternate or basal. Stamens 5 or more. Ovules numerous. Embryo circular 

 around the endosperm. I. Calandrinia. 



b2. Leaves alternate. Stamens 8 or more. Seeds numerous. Embryo slightly curved, and 

 endosperm scanty. Involucre consisting of dry imbricating bracts. Undershrub. 



2. Grahamia. 



