|r^Q LEMNACE.K. Lnnna. 



seed orthotropous, oblcii-, wiUi a i)roiniiient acute operculum. — Liniiiea, xxxiii. 

 2;51); lle^'olni. 1. c. l.'Ui, t. 7, lij,'. 1-8, uikI F1. Uras. iasc. 7G, t. 1, lig. iv. L. 

 Torrei/i, Austin; (Imy, Manual, 4 79. 



Ill si)rin"8 Liikc Comity (lli>land,r) ; iiboiit Sail Fraiicisoo (liolaiulcr, Kellogg k H"r/urd) ; Los 

 Angeles {Brewer) ; Northern Nevada (Z/'a/io/t) ; Arizona (/'a ///tcr), and eiistward to ihe Atlantic ; 

 also South American. 



3. L. minor, Linn. Fronds round- to elliiitic-obovate, 1 to 2\ lines in diame- 

 ter, rather thick, very obscurely 3-nerved : bract sacdike : seed obloiig-obovate, 

 am'phitropous, with prominent rounded operculum. — Nees, Oen. iii. t. 4l' ; llegelm. 

 1. c. 112, t. I), 10; Ueichenb. 1. c. 8, t. 14. 



l?ei)orted from various localities in California (Lobos Creek, Bolandrr, etc.), and ((mimon in all 

 quarters of the f^lobe — the most widely distributed of all the species, and UMialiy abundant, 

 closely covering the surface of stagnant pools. 



L. I'AircicosTATA, llegelm., may perhaps also be found in California, resembling L. viinor, Uyt 

 with orthotropous seed, and the .sheaths at the base of the young roots with broad wmg-hke 

 appendages ; bract reiiiform ; frond with a minute dorsal si)ine near the apex. 

 * * Ooules 2 to 7, anatropous: fronds venj thick and sponyy, Jlat above, very 

 ohscurelif 5-nerocd. — TELMAToniAot;, Hegelni. 



4. L. gibba, Linn. Fronds obovatc-elliptic to nearly orbicidar, almost hemi- 

 spherical, soon separating: bract sac like. — llegelm. 1. c. 145, t. 11-13; 

 Ueichenb. 1. c. 



Near San Francisco (Bohmdcr, in flower) ; Santa Barbara (7Vrm/) ; Arizona {rahner);\\\ the 

 Atlantic States, but rather rare ; in Mexico, the West ladies, and all .juarters ol the Old \\ oild. 

 A very peculiar and easily recognized si)ecies. 



2. SPEIRODELA, Schleiden. 



Anther-cells bilocellate by a vertical partition and dehiscent longitudinally. Ovary 

 2-ovuled. Frond 7- 1 1-nerved or more ; rootlets several, with axile vascular tissue. 

 Otherwise nearly as Ltmna. — A single species. 



L S. polyrrhiza, Schleid. Fronds round-obovate, purple beneath, 2 to 4 lines 

 in diameter, distinclly about 7-nerved ; roots clustered, usually 3 to 5 : l)ract sac- 

 like : ovules amphitropous. — llegelm. 1. e. 147, t. 10, and Fl. Lra.s. 1. c. iig. vi. ; 

 Austin, Torr. Lot. JUill. i. 37, ligs. ; Fngelm. same, i. 42. Lemna pulyrrldza, Linn. ; 

 lieichenb. 1. c., t. 15. 



Truckee River, Nevada (Watson); Oregon {Hall); and found in all (piarters of the globe, 

 but not yet reported from within the limits of California. It is very rarely detected in llower or 

 fruit, though often very abundant. 



Order CXIV. NAIADACE^. 



INIarsh or mostly immersed aquatic herbs, with stems jointed and leafy or (in 

 Triglochin) naked and scape-like, leaves sheathing at base or stipulate, and flowers 

 perfect or unisexual, often spathaeeotis, with perianth of 4 or G herbaceous distinct 

 valvate segments, or membranous and tubular or cup-shaped, or none ; stamens 1, 

 2, 4 or G, with extrorsu anthers; ovaries 1 to G, distinct or more or less ct)herent, 

 1-celled, usually 1-ovuled, in fruit follicular or capsular or an indehiscent berry or 

 utricle ; albumen none ; embryo large, often curved. 



An Older (as liere undeistoo<l, embracing the Jnncai/iueci:) of about 20 genera and 70 or more 

 specie.s, widely distiibut.d chielly through temperate and cooler regions, both in fie.sh and saline 

 waters. Th.M-e is much diveiMty in the chaiaetns of the gern'ra. Will, lew ex.eptions the 

 Californiau species are the same as those on the Atlantic coast, and are also lound lu the Old 

 World. 



