^■'«'»««- LEMNACPL-E. -,j,q 



l:vtc flowers without bracts : pollen-grains in fours. - Eohrbacli, Vcrl,.Ver. Brandenb 

 XK 38, and Anier. Journ. Sci. 3 ser. ii. 375 ; Keiclienb. Icon. Vl Germ i' r s's 



A,^S°;n;n,;'^"'SKl''wo..ld" '^^""""^^ '"'•^''"•^^^•' ^''^ '"""^ ^>-o'-t .noslof I^lnh 



bnr^i; .^'l^'fF!'^*'^';^'?' ^ ■'""; ■^?,'''' ^''"'"^ narrower, somewhat convex on tlie 

 back : MS , Hate a.id stammato inllorescence usually separated by a short interva^^ 



witif^: Ih. rT'"' ' "[ V"-'ir ;'""'",^'^ ■ I-'^--o'-- 3i'»Ple : pistillat io V rs 

 I c ; lleichenb'rc^'f sVr." ' ^"^ ^''''"^^ "' ''^' «"'"'"it- -liohrbach, 



CoUectejl at So.la Lake in Soutlieastern California {Dr. Cooper) and at Los An<relp, (Rrv T r 

 Nevm) ; also m the Atlantic States, but less conunon than tlie last, ami in tL uf.l wS" 



Order CXIII. LEMNACE^. 



Very small floating herbaceous perennial stemless plants, consisting of flattened 

 disk-liko fronds, with usually one or more rootlets from the middle below • florets 

 imbedded in the frond, without perianth, nake.l or bracteate, with 1 or 2 stamens 

 and a sessile 1-celled 1 - several-ovuled ovary (each organ by some botanists 

 sidered a distinct flower) ; style simple, with funnelform stigma ; ovules at the .... 

 of the cell; fruit a utricle; seeds comparatively large, albuminous with straic^ht 

 axile embryo, the testa operculate at the apex. - Ilegelmaier, Die Leranaceen ° 



Rushed by Its nunute size, the thick rootles/ fronds being only i toloTal.tbm d The 



ilouers are naked, and have a sin^de stamen with a 2-cellea a^nther, Ld a 1-ovuled ova.y 



1. Lemna. Frond 1 - .-i-nerved, with a single rootlet. 



L Spirodela. Frond 7- ll-nerved, with several rootlets. 



1. LEMNA, Linn. Duckweed. Duck's-meat. 

 Flowers marginal, bracteate, diandrous. Filaments slender; anthers didymou. 

 each cell bilocellate by a transverse partition, dehiscing transversely. Seeds 1 to g' 

 mostly ribbed. -Frond 1-5-nervcd, containing numerous acicular raphides pro- 

 liferous from a lateral slit (usually on each side) near the base, with a sin<^le rootlet 

 which is destitute of vascular tissue. ° ' 



* Ooule solitary, orthotropoHs or nearbj so : froidl - 3-nerved, thin.—. 



ts con- 



Lemna 

 proper. 



-1- Fronds ohlong, stalked at base, remaining connected. 



1. Ii. trisulca, Linn. Fronds thin, oblong or oblong-lanceolate, 6 to 9 linos 

 Jonrr, attenuate at base, into n bIp.., lor =.t..ii. ,.„„„ „u., i.. o ,' .. «'. ;""^s 



lOUt 



ike 



iong attenuate at base into a slender stalk, very obscurely 3-nerved, often witho, 

 rootlets, usually several series of offshoots remaining connected : bract sac-like • 



seeds ovate, amphitroi)ous, with small round operculum. — Hegelm. 1. c 134 t 6 G- 

 Iveichenb. Icon. Fl. Germ. vii. 9, t. 1.5. >"•">", 



^J'Zt^jT'''^ "'^"'1°" S^?" f;--^^"'"! ^'^^^ (Bigclota) ; Plnmas County (Lcmmon) ; Oregon, 

 and eastward thro.igh most of North America, as also through Europe, Asia and Australia. 



-»- •»- Fronds oblong to elliptical or round-ovate, sessile, soon separating. 

 2. L Valdiviana, Philippi. Fronds elliptic-oblong, small (a lino Ion- or 

 usually less, rarely more), rather thick, obscurely l-nervcd : bract broadronifiTrm : 



