406 DK, A. B. KEXDLE — SYSTEMATIC 



Najas Jtexilis, Griseb. Veget. Karaib. 110 (1857), non Kostk. 

 " \2lv. guadalvpensis, A. Br. in Jourri. Bot. ii. {1864) 276. 

 Yar. fusifor mis, Chapm. Fl. South. U. S. 444 (1860) ; Morong iu Bot. Gaz. x. (1885) 256, & in Bull.. 

 Torr. Bot. Club, xiii. (1886) 160. 

 N. guadalupensis,Morong\n Mem. Torr. Bot. Club, iii. no. 2 (1893), 60, t. 67; K. Schura. in Mart. Fl. Bras, 

 iii. pt. 3, 726 (1894), t. 124. fi^. 1 ; Britton & A. Brown, 111. Fl. North. U. S. i. 81, fig. 181 (1896). 

 Qaulin'ta guadalupensis, Spreng. Syst. i. 20 (1825). 



Monoica, debilis, diffuse ramosa, iiiternodiis tenuibus, interdiim subfiliformibus ; foliis 



patentibiis, interdum flexuosis, planis vel margine plus ininusve crisp ulatis, lineari- 



bus, cum apice obtusiusculo vel plus minus acuto, et margiue spinulis ininutis 



numerosis ascendentibus instructa ; vaginis in parte superiore cum dentibus paucis 



subprominentibus instructis ; squamulis intra vaginalibus angustis, ssepe e basi latiore 



filiformibus ; Jlorlbiis masculis solitariis, ssepe breviter pedicellatis, spatlia ellipsoidea 



vel ellipsoideo-oblonga cum coUo sub ore spinulis acutis instructo ; antliera quadrilocu- 



lari ; pnlline oblongo ; femineis solitariis vel geminis vel fasciculatis, ovario nudo 



oblongo, stylo valido cum stigmatibus saepe duobus, process ubus spiniferis binis 



superadditis, interdum stigmatibus tribus ; fructu parvo anguste ellipsoideo vel ellip- 



soideo-oblongo ; semine ruguloso cum areis subquadratis in seriebus longitudinalibus 



15-18 manifeste exsculpto. 



Habit very variable, depending on the degree of branching, the diameter of the stem, 



the length and breadth of the leaves, and the flat or more or less crisped character of 



the leaf-blade. 



The long, slender, weak branches bear leaves at fairly regular intervals along their 

 whole length. Leaveslto 2-5 cm. (often about 1-5) cm. long, by '410 1 mm., often about 

 '5 or '75 mm. broad ; marginal spine-cells yellow, generally visible only under a lens, 

 from 20 to 45, according to the length of the leaf, sometimes extremely small and blunt, 

 at others longer and sharply pointed. The level of the epidermis is sometimes broken 

 ooly by the spine, sometimes raised slightly about the insertion of each spine. In a 

 plant from Nicaragua ( Wright) the spines are sometimes supported on a base of 2 to 3 cells 

 projecting from the epidermis, forming more conspicuous teeth. Leaf-apex with one or 

 a pair of sharp spines. Sheath 1-5 to 2 mm. long and as broad ; spines on sloping 

 shoulders 4 to 10, sharply pointed, and borne on a several- celled base. Male Jloioers from 

 2-3 to 3 mm. long, with a longer or shorter neck, which may reach '0 mm. in lensth. 

 Female floicers 2-5 to 2-75 mm. long, showing great variety in the number of stigmas and 

 spine-bearing processes. Fruit in clusters of 2 to 5, narrow, sometimes oblique, fairly 

 uniform in shape and size ; about 2 mm. long ; pericarp conforming closely to the seed. 

 The 4- (sometimes 5- or 6-) sided areolie are very plain iu the middle of the seed, becoming 

 smaller and less distinct on the sides and towards the base and apex. 



The most general form of female flower has two more or less ligulate stigmas and a 

 pair of longer, slender, spine-tipped processes decussating with them ; but there may be 2 

 stigmas only, or 3 stigmas, or 2 stigmas and 1 spine-arm (a frequent variation), or 1 stigma 

 and 2 spine-arms, or 3 stigmas one of which bears a brown spine-cell, or 2 stigmas and 

 a structure \v hich is part stigma, but drawn out on one side into a narrow spine-arm. 



