MACLOSKIE : POLYGONACE^E. 351 



(Old World, and nat. in U. S.); Magellan (Dusen); near Carmen de 

 Patagones. 



4. POLYGONUM Linn. 



Flowers perfect, in terminal or axillary clusters. Calyx 4-5-parted, 

 outer segments the larger. Style 2-3-parted, the stigmas capitate. 

 Achenes invested by or exceeding the calyx. 



Species 200, cosmopolitan save in the tropics ; several in Chili, few in 

 Brazil and Argentina. 



KEY TO THE SPECIES. 



A. Leaves lance-linear to oblong. Sheaths lacerate. Axillary flower-clusters. camporum. 



Az. Leaves lanceolate, acuminate both ways, style 2-parted. ferrugineum. 

 A$. Leaves oblong-linear. , 



b. Sheaths silvery, 2-parted. Flowers small, in axillary clusters. aviculare. 



bz. Sheaths at length lacerate. Flowers in 3's, peduncled. chilense. 

 A^. Leaves elliptical to obovate. 



b. Sheaths bifid at first. Branches prostrate. Flowers fascicled. delfini. 



b2. Sheaths large, bifid or lacerate. Flowers none-3, axillary, pediceled. maritimitm. 



A$. Leaves ovate-sagittate, the upper narrower, long-petioled. Stem twining. convolvulus. 



i. P. AVICULARE Linn. 



Slender, glabrous, prostrate herbs, with oblong-linear, or oblanceolate, 

 acute, subsessile leaves, jointed to the silvery, 2-parted sheaths. Flowers 

 small, 1-5 in axillary clusters. Calyx 5-parted, green, bordered white 

 or pink. 



(Eurasia and N. Amer., a weed in cultivated lands); N. Patagon.; 

 Magellan. (Dusen.) 



2. P. CAMPORUM Meisner. 



Glabrous, tall, slender-branched annual or perennial. Leaves sessile, 

 linear-lanceolate to oblong, obtuse, 6-25 mm., deciduous with the lacerate 

 sheaths. Flowers several, in axillary clusters, short-pediceled. Stamens 

 8. Achene trigonal, shining-black. 



(N. Amer. in prairies, extending to S. Amer.); S. Patagon., by Rio Sta. 

 Cruz. 



P. CAMPORUM AUSTRALE Meis. 



Upper leaves subulate-linear, revolute-margined. Calyx less than ?. 

 mm. long. 



(Argentina.); mouth of Rio Chubut. (Dusen.) 



