KEVISION OF THE GEXL^8 NAJAS. 401 



prominenti])us freqiientius instructo ; vagina cyliadrica breviter auriculata, auriculis 

 obtusis irregulariter spinosis ; Jloribus solitariis, muscuUs breviter pedicellatis, spatha 

 oblonf^a superne in collum late cyliiidricum ore irregulai-iter deiiticulatuiu transieiitc; 

 anthera uniloculari ; femineis subsessilibus spatha anguste ovali-oblonga cum collo 

 cylindrico, ore pauci-spinifero, stylo in stigmata duo diviso ; fructu et semine .... 

 Judging only from the fragmentary specimens (whicli were mixed with ^. graminea\ 

 a small plant with spreading branches. Leaves thin, slender, tapering, 1-4 to 2-1 cm. 

 long by -4 mm. broad (without the teeth) ; marginal teeth about a dozen, subtriangular, 

 ending in an upwardly-pointing brown spine, 'm. length about half the leaf-width; apex 

 ending in one or a pair of spines. Sheath 2 to 3 mm. long ; auricles with 3 to 4 erect teeth. 

 Male jiowers about 2 mm. long before dehiscence of the anther, spathe below its neck 

 fitting closely to the perianth, which has a markedly bilabiate top above the anther. On 

 dehiscence the spathe splits from above downward and the anther is carried up on a 

 long stalk, the whole flower measuring 3'5 mm. long. 



Female jiowers very shortly stalked, about 2-25 mm. long, the spathe conforming to 

 the ovary below, and produced into a neck surrounding the long style, whicli ends in two 

 short unequal stigmas protruding beyond the mouth. The specimens bear no ripe fruit. 

 Tropical Africa — Grosse Seriba Ghattas, Djur-land {Schweinfiirth, no. 2140 in part). 

 (Mixed with N. gramlnea.) 



Near N. JFelivltschil, but distinguished by its narrower auricled sheaths and smaller 

 male flowers. 



4. Najas Welwitschii, Rendle. (PL XXXIX. figs. 46-52; PI. XL. figs. 53, 54.) 



N. Welwitschii, Rendle, in Welw. Cat. ii. 95 (1899). 

 Najas sp., Magnus, Beitr. 44-, 45, t. 5. fig. 18 (1870). 



Herba laete viridis, lucidula, caulibus ramisque effusis ; folils planis lineari-angustatis, 

 in vivo patentibus, margine dentibus frequentibus ascendentibus subprominentibus 

 instructo; vaginis late rotundatis vel truncatis, cum denticulis numerosis superne 

 marginatis, sajpe asymmetricis ; squamulis intravaginalibus subulatis ; Jloribus 

 solitariis, spatha mascula ellipsoidea, cum collo breviter cylindrico, ore spinifero; 

 anthera quadriloculari ; spatha feminea ut in mari, sed cum collo longiore 

 (? bilabiato), stylum et stigmata duo celanle ; fructu spatha incluso, demum a semine 

 maturo ellipsoideo-oblongo, apice angustato, rupto ; testa cum areolis quadratis 

 distinctis numerosis lineata, rapliei prominente. 

 *' Swimming at the bottom of water, usually in not very deep water, rooting in the 

 mud bv a long root-fibre-bearing rhizome." 



Shoots spreading, rooting copiously at the nodes, the longest 30 cm., branches spreading ; 

 lower internodes reaching 4 to 5 cm. in Icngtli l)y 1 mm. in width, becoming gradually 

 smaller on the 1)ranches, the upper being aljout 1 cm. long by 5 mm. in width. 

 Branchlets and leaves in the dried specimens limp and flaccid, hanging together; but 

 the leaves are described as spreading in the living state. Leaf-blades generally 2 to 2*5 

 cm. long by '4 to -5 mm. in greatest width above the sheath, with an evident midrib and, 

 on the older leaves, transverse markings, especially in the lower part ; marginal teeth, 

 o-enerally 12 to 16, broadly subtriangular, ending in an ascending brown spine : in the 



