4 CYMODOCEACEAE. 



Family 1. ZANNICHELLIACEAE. Pondweed Family. 



Aquatic caulescent herbs. Leaves alternate, filiform or with broad 

 blades, entire. Flowers j^erfect or monoecious, in spikes or clusters, from 

 a spathe. Andoecium of 1, or mostly 2-1 distinct stamens. Gynoecium 

 of several distinct carpels. Fruit a cluster or spike of drupelets. 



Stamens 2 or sometimes solitary, the connectives without appendages : drupelets 

 manifestly stipitate. 

 Stigma terminating a long style : anther 1. 1. Zaxnichellia. 



Stigma sessile : anthers '2. 2. Ruppia. 



Stamens 4, the connectives with dilated appendages : drupelets 



sessile. 3. I'otamogeton. 



1. ZANNICHELLIA L. Delicate herbs of fresh or brackish water. 

 Leaves with narrow blades and inconspicuous bases. Flowers monoecious: 

 stamiuate with 1 stamen; pistillate with 2-6 carpels together. Drupelets 

 clustered, curved, crested. 



1. Z. palustris L. Leaves 2-7 cm. long, acute : drupelets 2-4, or sometimes 6, 

 together, the body 2-4 mm. long, short-stipitate. — Everglades and creeks. 



2. RUPPIA L. Delicate herbs of salt or brackish water. Leaves with 

 slender blades and conspicuous bases. Flowers perfect. Stamens 2. Carpels 4. 

 Drupelets clustered, oblique, crestless. 



1. R. maritima L. Leaves 2. .5-4 cm. long, capillary at the apex: drupelets 

 few, the body ovoid, gibbous at the base, loug-stipitate. — Creeks.— F. K. {Ber., 

 Bah., Cuba. Ant.). — Ditch-grass. 



3. POTAMOGETON L. Herbs growing mostly in fresh water. Leaves 

 various, the submerged and floating ones different. Flowers perfect, spicate. 

 Stamens 4, with appendaged anthers. Carpels 4. Drupelets 4 together, spicate, 

 sessile. — Pondweed. 



Leaves with dilated blades ; stipules free from the leaf-base. 1. P. lucens. 



Leaves setaceous or filiform ; stipules adnate to the leaf-base. 2. P. pectinatus. 



1. P. lucens L. Plants submerged: leaf -blades elliptic or lanceolate, or oval 

 above, 5-20 cm. long, acute or acuminate, often serrulate at the apex, nearly 

 sessile: drupelets about 3 mm. long, slightly keeled. — Everglades. — {Cuba.) 



2. P. pectinatus L. Plants submerged: leaves setaceous or filiform, 2-15 cm. 

 long, sessile: drupelets 3.5-4.5 mm. long, crestless. — Streams. — (Cuba.) 



Family 2. CYMODOCEACEAE. Cymodocea Family. 



Submerged herbs with jointed rootstocks. Leaves clustered at the 

 nodes or on short branches, each with a sheath and a naiTow blade. 

 Flowers monoecious or dioecious. I'erianth wanting. Androecium of a 

 sinji'le anther terminating a long ])edicel. Gynoecium of 2 distinct inequi- 

 lateral cari)els, each terminating in a style and 2 elongate stigmas. Fruit 

 a pair of obliquely ovoid achenes. 



1. CYMODOCEA Koenig. Rootstocks elongate. Flowers hidden in the 

 leaf-shcaths. 



1. C. manatorum Aschers. I'lants growing on sandy bottoms, the short stems 

 arising at the nodes: leaf -blades narrowly linear, 5-25 cm. long: fruits 6-7 mm. 

 long, short-stipitate, prominently beaked. — Bay Biscayne. — F. K. {Bcr., Bah., 

 Cuba, Ant.). 



