EEVISION OF THE GEXtTS NAJAS. 423 



margins armed with large triangular spreading teeth, longer than the leaf-width, ending 

 in a small, rigid, dark brown spine. In robust specimens the blade reaches 2 cm. in 

 length by -75 mm. in width about the middle, w^ith about 8 teeth projecting 1 mm. from 

 tlie margin in the lower half, becoming shorter as the leaf narrows above, but still 

 slightly exceeding its wddth; the midrib is prominent, and narrow bands run at right 

 angles from it towards the margin ; the broad truneately-rounded sheath is 25 to 3-3 

 mm. long by 175 to 3-3 mm. broad ; the rounded shoulders bear from 4 to 6 minute 

 teeth, decreasing in size from above downward. In the more delicate specimens the 

 blade is 8 to 11 mm. long by -5 mm. broad, bears 4 to 6 teeth exceeding the leaf-width, 

 and the sheath is about 1*5 mm. long. Intravaginal scales -75 mm. long. 



Male flowers 25 to 3 mm. long ; spathe-neck cylindrical, scarcely -5 mm. long, the 

 mouth bearing a few short spines ; perianth subelliptical, narrowing abruptly below the 

 two-lipped apex. Ovary 2iho\\.t 2 mra. long; stigmas broad, spreading, linear-tapering. 

 Fruit 2 to 25 mm. long, tapering above, and crowned with the withered style and 

 stigmas. Seed plainly marked with about 20 rows of squarish pits. 



Tropical Aprica — Central and East : Gazelle river {Schtcewfurth, nos. 1137 in part, 

 and 1228 in part) ; Pazogl (>S^. Ange) ; Lake Tanganyika {Uore) ; Ressano Garcia, 

 Mozambique [ScJilechter, no. 11883). West: Nupe (Barter, no. 1065), Cameroon 

 (Freuss, no. 452 ; Staudt, no. 488) ; Lac de Ghier, Senegal (Roger) ; Marais du 

 Walo, pr^s Keurmbaye (Leprieur). 



Note. — I find no evidence of the spathe which Magnus describes and figures for this 

 species (see Ber. Deutsch. Bot. Ges. xii. (189i) fig. 2). I have not seen the Egyptian 

 specimen on which the account is based, and it may perhaps represent another species. 



30. Najas iNTERRUPrA, K. Sclium. in Engl. Pflanz. Ost-Afr. Th. C, 94 (1895) ; Arth. 

 Bennett'in El. Capens. vii. 51 (1897). 



Eusco-viridis, caulibus gracilibus rigidulis, internodiis teretibus inermibus elongatis ; 



foliis e vagina magna brevibus lineari-angustatis obtusiusculis, margine irregulariter 



paucidentata, dentibus in parte inferiore lamina? latitudinem 9equantil)us robustis 



triangularibus patentibus, aculeo brunneo-rufescente ascendente terminatis, superne 



deminuentibus et pro rata brevioribus ; vaginis saepius asymraetricis, in folio 



superiore cujusque paris majore, humeris saepe latissime rotundatis, interdum plicatis 



plus minus truncatis, superne cum denticulis paucis minutis instructis ; squamulis 



intravaginalibus lanceolatis vel triangulari-lanceolatis acutis ; floribus solitariis, 



spatha mascula ellipsoidea apice in coUum cylindricum desinente, ovario nudo 



anguste ellipsoideo, stylo cylindrico in stigmata bina (vel terna) apice aculeata 



desinente ; fructu fusiformi ; testa cum areis quadratis in seriebus circa 20 ordinatis 



manifeste exsculpta. 



Habit rather straggling and wdry. Internodes 1*5 to 2 cm. in upper part of shoots. 



Leaves about 1 cm. long, including the sheath, about '5 mm. greatest breadth, not 



including the teeth ; margin asymmetrically toothed, 5 or teeth on each side. Sheath 



2 to 3 mm. long by 1*7 to 275 mm. broad, with 3 to 6 small teeth on each shoulder; 



that of the upper of each leaf-pair larger, more asymmetrical, and markedly amplexicaul. 



