MACLOSKIE: VALLISNERIACE/E. 153 



2. E. PATAGONICUS Speg. 



Striate leaved, simply-scaped, subdecandrous, low. Leaves membra- 

 naceous, ovate-cordate or subhastate, with obtuse lobes and apex, 5-7- 

 nerved. Scapes trigonous, exceeding the leaves, bearing 2-3 verticils 

 with 3-6 flowers in each verticil ; pedicels long ; flowers small ; stamens 

 erect, flavescent Carpels very many and small, dimidiate-obovate, lat- 

 erally compressed and nervose, with a long gland between the nerves. 

 Style subterete, as long as the carpel. 



N. Patagon., Neuquen near Fort Roca. 



2. SAGITTARIA Linn. Arrowhead. 



Perennials with nodose rootstocks, the leaves long-petioled, nerved and 

 with cross-veins, or reduced to bladeless phyllodes. Flowers monoecious 

 or dioecious, the staminate usually uppermost in the panicle. Verticils 

 3-flowered, 3-bracted. Petals white. Achenes in globose heads. Leaves 

 often arrow-shaped. 



Species 30, in temperate and warm climates. 



S. MONTEVIEDENSIS Cham. & Schlecht. 



Leaves sagittate, rough on the margin and on the nerves and veins of 

 the under surface. Anthers linear, yellow. Filaments longer than the 

 anthers, subulate, hirt. 



(S. Brazil) ; N. Patagon. ; common near Rio Negro by Carmen. 



Family 9. VALLISNERIACE^;. Tape-grass. 



Submerged and floating long grass-like herbs, with regular dioecious 

 flowers appearing above a 3-leaved remote spathe. Inner perianth petaloid. 

 Ovary i-locular, with 3 parietal placentae. Fruit ripening under water, in- 

 dehiscent. Seeds numerous. 



VALLISNERIA Linn. 



Floating in quiet streams. Staminate flowers minute, many in the 

 spathe, on a short scape early separating and floating freely on the sur- 

 face of the water. Pistillate flowers solitary on a very long spirally twisted 

 scape, the perianth-tube adnate to the ovary, with three small petals. The 

 scape by unrolling elevates the pistillate flowers to the surface, where they 



