PONDWEED FAMILY. 7g 



Three or four species occurring in salt and brackish waters all over the world The folio. 



are the only ones known to occur in North America: 



Sheaths 3" -4" long; drupes about i" long. , 



Sheaths 1 A'-1 1 A' long; drupes i'A"-2" long. 



2. Ruppia occidentalis S. Wats. 

 Western Ruppia. (Fig. 177.) 



Riif>t>ia occidenlalis S. Wats. Proc. Am. Acad. 

 25: 138. Sept. 1890. 



lacustris Macoun, Cat. Can. PI. 5: 372. 

 Nov. 1890. 



Stems stouter, i-2 long, the branching 

 fan-like. Leaves 3 / -8 / long, their large 

 sheaths > / -iX / long ; branches and leaves 

 often thickly clustered at the nodes, the 

 sheaths overlapping each other ; drupes 

 larger, i^ // -2 // long, ovoid or pyriform, 

 borne on pedicels about \' long, the pe- 

 duncles bright red when fresh and some- 

 times nearly 2 in length. 



In saline ponds, Nebraska to British Co- 

 lumbia. Summer. 



i. Ruppia maritima L. y 

 time Ruppia. l-i K . 176.) 



Knf>f>ia niaiithiKt I. Sp I'l i r; 



Stems often whitish, a-3 long, the 

 internodes irregular, naked, i'-3' long. 

 Leaves i'-tf long, X" or lew wide; 

 sheaths 3"- 4 " long, with a shor 

 tip; peduncles in fruit sometime* i 

 long; pedicels 4-6 in a cluster, #'-l#' 

 long ; drupes with a dark hard ' shell, 

 ovoid, about \" long, often obli-, 

 gibbous at the base, pointed with the 

 long style, but varying much in shape ; 

 forms with very short peduncle* and ped- 

 icels, and with broad, strongly marked 

 sheaths occur. 



Common in brackish or Halt water alone 



the Atlantic and Pacific C'ast- 

 Aiiu-rica and in salii: 



tenor. Widely di-tribi:t <1 i:i the- >M World 

 and in South America July AUK 



3. ZANNICHELLIA L. Sp. PI. 969- '" 



Stems, flowers and leaf-buds all at first enclosed in a hyaline envelope, corre*poi 

 the stipule in Potamogeton. Staminate and pistillate flowers in the same axil 

 nate solitary, consisting of a single 2-celled anther, borne on a short pedi 

 the pistillate 2-5. O/ary flask-shaped, tapering into a short style ; stigma I 

 somewhat cup-shaped, its margins angled or dentate. Fruit a fl 

 or sometimes toothed on the back. Embryo bent and coiled at the cotyledt 

 honor of J. H. Zannichelli, 1662-1729, Italian physician and botanist.] 



Two or three species of very wide geozraphic distribution in fresh-water pond* and * 



