220 CLIII. NAIADACE^ (bBNNETT). [AywWS. 



muricate stems. Leaves linear, entire, or toothed, alternate, opposite, 

 or whorled. Flowers dioecious or monoecious, axillary and small. 

 Species about 32, in all temperate and tropical regions. 



Dioecious 1. iV^. marina. 



Monoecious. 



Msile and female flowers without a spathe . . 2. N. graminea. 



Male and female flowers in a spathe. 



Female spathe with a terminal outgrowth . . 3. ^. ajfflnis. 

 Female spathe without a terminal outgrowth. 



Sheaths with short obtuse auricles . . . 4. iV. Schioeinfurthii, 



Sheaths truncate or rounded . . . . o. N. Welwitschii. 



Male flowers only in a spathe. 



Anthers 1-celled • . . . . • . Q. N. minor. 



Anthers 4-celled. 



Leaves falcate 7. JV. Tiorrida. 



Leaves not falcate 8. iV". intermpta. 



1. N. marma, Linn.^ var. muricata, Al. Br. ex K. Schum. in 

 Mart. Fl. Bras. iii. iii. 725. Stem thickly covered with spines. Leaves 

 linear, with 14-20 patent triangular marginal teeth, which are generally 

 longer than the blade is broad, and with about 5 on the back ; sheaths 

 rounded at the edges, each with 2 teeth on the edge, and 1-3 spines 

 on the back. — Rendle in Trans. Linn. Soc. ser. 2, Bot. v. 397, 440. 



Xflle Ziand. British East Africa : in the Albert Nyanza, SUihlmann, 2841 (ex 

 Rendle). 



2. N. graminea, Del. Fl. Fgypte, ii. 282, t. 50, Jig. 3. Stems 

 elongated, rooting at the lower nodes, from a few inches to 2 ft. long. 

 Leaves linear, narrowing upwards, spreading-recurved, sometimes with 

 a plumose habit, and other times lax and weak, with 36-40 teeth on 

 the margins ; sheaths elongated, with pointed lanceolate auricles, and 

 S-10 teeth on the margin. Flowers in the axils sometimes female 

 only, sometimes with a male and female side by side. Male perianths 

 ending above the anthers in the ear-like lobes. Fruits solitary or 2-4 

 together, narrow-oblong, or ellipsoid-oblong, tapering at the apex. 

 Seed-testa marked with 25-30 regular lines of small areolae. — Durand «t 

 Schinz, Conspect. Fl. Afr. v. 499; Kunth, Enum. iii. 115; Schweinf. 

 Beitr. Fl. Aethiop. 194 and 292. 



Iffile Ziand. Kordofan : Omkenem, near Arashkol Mountain, Sfevdner, 213 I 

 British East Africa : Jur ; Kurshook All's Seriba, Schioeinfnrth, 1217 ! Jur 

 Ghattas, Schtoeinfurtk, 2140 partly! Kinani, in the East Ongalea Mountains, 

 Gregory ! 



Widely distributed in the Eastern Hemisphere. 



3. N. affinis, Rendle in Trans. Linn. Soc. ser. 2, Bot. v. 440. 

 Stems slender. Leaves with 12-18 teeth on either margin, a quarter 

 of the leaf -width in length ; sheath irregularly broken on the upper 

 margin and shoulders into short narrow outgrowths, tipped with spine- 

 cells, the outgrowths may extend almost to the base of the sheath. 

 Female flowers apparently not quite mature. Spathe ellipsoid with a 



