EE VISION OF THE GENUS NAJAS. 407 



These variations, and especially the occurrence of transitional structures showing both 

 the irregular pajjilliform surface of a stigma and the uniform ribbon-like character of 

 the spine-arm, indicate that the spine-arms are only barren stigmas. 

 In still or flowing water. 

 North America — Texas (Hall, no. 618 ; Lludheimer, no. 705 ; Brmnmond, no. 436) ; 



California, San Francisco [Adoltz) ; West Texas to New Mexico ( Wright, no. 678) ; 



Florida (Chapman). 

 Central Ajierica — Mexico (Schaffner, no. 227 ; Ilahn ; Mueller, Orizaba ; Schiede, 



no. 814 ; Fahyier, Durango, nos. 157, 704, 708) ; Guatemala (JBeruouilli, nos. 



206, 818, 1068) ; Nicaragua ( JVrlffht ; Tale, no. 398). 

 West Indies — Guadeloupe (Diichassalng) ; Cuba ( TFright, nos. 72, 74, 70, 77 ; Combs, 



no. 707); Jamaica (Swartz) ; Porto Ptico (Sudenis, nos. 852, 1060, 2330, 3803). 

 South America — Caracas (JErnst, no. 4, " in rivulo Caroate ") ; Uruguay, Rio 



Fernandez (Niederlein, no. 214) ; Argentina (Ilieronymus, no. 553, " Laguna del 



Palmar cerca de San Jose, Oran": no. 745, " Lagunas de Bajo del Manzano, 



Provincia de Cordoba "). 



Var. curassavica, A. Br. in Sitzungsb. Ges. Naturf. Fr. Berlin, 1868, 17, extensa. 

 N^flexilis varr. curassavica et Gollmeriana, A. Br. in Jourii. Bot. ii. (1864) 277. 

 Planta robustior, suberecta, minus et rarius diffuse ramosa ; foliis latioribus sospissime 

 planis, 



A stronger growing plant, 10 to 20 cm. high, the specimen from Florida ( 72 ?<^^Z) alone 

 having the weakly habit and markedly crispulate loaves of the type. Leaves 1'2 to 2^7 

 cm. long, generally about 20 cm., 1 to 1'75 mm. broad, generally about 1*5 mm., with 30 

 to 50 teeth on the margins. 



North America — Florida (Huegel). 



Central America — Alexico (Schaffner-, Hahn). 



W^est Indies — Porto Eico (Sliitems, no. 2533); Cuba (Wright, 605 in Herb. Kew.). 



South America — Caracas (Seematin; Gollmer; Ernst, Najades, nos. 1, 2, 5, 1765 «) ; 

 (Spruce, no. 6456). 



It is difficult to draw a hard-and-fast line between the variety and the species, though 

 most specimens can easily be relegated to one or the other. 



10. Js^'ajas punctata, sp. nov. (PI. XL. figs. 99-102.) 



N.fiexilis \^v. punctata, A. Br. in Journ. Bot. ii. (1864) 277. 



Planta caulibus rigidis, ramis brevibus ; foliis subascendentibus, rigidulis, punctatis, late 

 linearibus, superne angustatis, nervo centrali consj)icuo, spinis marginalibus mao-nis 

 cum cellulis binis super marginem elevatis l)asi munitis ; vaginis validis in laminam 

 gradatim transgredientibus, squaraulis intravaginalil)us lanceolatis ; florihiis solitariis, 

 masculis A. microdontis, femineis cum stigmatibus binis, processu spinifero iuterdum 



superaddito ; fructu 



The straight stiff stems, with their short branches, afford a characteristic habit. Leaves 



tough and strong, about 18 cm. long and 1-5 mm. broad; sheath 28 mm. broad, with 



