1712 CXLVIII. NAIADES. [Zostem. 



folded inwards over some of the flowers.— -Z^. marina, Hook. f. Fl. Tasm. ii. 44, 

 rand E. Br. Prod. 338 '? partly; Z. Mudleri, Irmisch ; Asehers. in Linnaeai, 

 XXXV. 168. 

 Hab.: Southern coast. 



6. NAIAS, Linn. 



(A water-nymph.) 

 (Caulinia, Willd.) 

 Flowers unisexual', solitary in the axils of floral leaves,, sessile or shortly 

 ipedicellate. Male flower : Anther single, 1 or 4-celled, enclosed in a thin 

 membranous bract or perianth, irregularly lobed at the top and often splitting 

 and rolling back so as to disclose the apex of the g-nther ;! pollen globular. 

 Female flowers sessile. Perianth none besides the bract.. Carpel. 1, tapering into 

 •a style divided into 2, 3 or sometimes 4 stigmatic branches; ovule 1, erect. 

 Fruit a small indehiscent oblong or cylindrical nutlet. Seed erect, with a hard 

 testa ; embryo straight, with a prominent plumula. — Submerged fresh-water or 

 subsaline herbs, with slender branching stems. Leaves' linear, in pairs or 

 ■clusters so as to appear opposite- or verticillate, bordered by minute or prominent 

 acute or pungent teeth, dilated at the base into a membranous sheath often 

 iproduced on each side into hyaline toothed or ciliate stipular lobes. 



The genus is widely spread over the temperate and tome oi the warmer regioirs of the globe. 

 'Leaves prominently toothed almost pinnatifid, the .basal sheath not produced 



into scarious stipules . . , 1. N. major. ' i 



Leaves very narrow, the teeth very minute, the basal sheath produced on each 



side into a broadly lanceolate stipular lobe ■■.... 2. N. temiifolia. 



1. KT. major (greater), ./4M. ; Eunth, Eniim. iii. 112; Benth. Fl. Austr. vii. 

 181. Leaves linear, bordered by broad triangular acute very prominent teeth so 

 as to be almost pinnatifid, \ to nearly lin. long, dilated at the base into a very 

 short broad toothed sheath not different in texture from the lamina nor produced 

 into stipular lobes, aculeate on the back as well as the stem but the prickles 

 tfew or so minu,te as to be difficult to see on the dried specimens. Flowers 

 ■dicBcious. Male perianth oblong, consisting of a thin-membranous sac entirely 

 ■enclosing the anthers, 2 or 3- toothed and at length bursting irregularly at tiie 

 top. Anther sessile, 4-celled. Female flower a single oblong carpel with 2 or 



■3 linear stigriiatic lobes, the ripe nutlet about 1 J hne long.— F. v. M. Fragm, 

 •viii. 218 ; Nees. Gen. Fl. Germ. Ic- 



Hab.: Flinders Eiver, F. v. MuHler ; Tweed River, F. t'. Mueller. 

 The species is widely spread over the northern hemisphere. 



2. Mr. tenuifolia (leaves thin), 11. Br. Pn-jd. 345 ; Smth. Fl. Austr. vii. 181. 

 :Stems slender, miich branched. Leaves very narrow linear, flat and transparent, 

 ■mostly about lin. long, 1-nerved, bordered by rather numerous very minute teetli 

 •often only visible under a strong lens, the sheathing base very short but produced 

 on each side into a rather long broadly lanceolate ciliate-toothed stipular lobe. 

 Male flower stipitate, oblong, about \ line long. Female carpel about 1 line 

 long, oblong-cylindrical, produced into a filiform deeply 2-branched style as long 

 as the carpels. — F. v. M. Fragm. viii. 219. j .-'' , 



Hab.: Common in the southern watfers. 



7. CYMODOCEA, Keen. 

 (After a sea-nymph.) 



(Amphibolls, Agardh.) 



Flowers unisexual, solitary within sheathing bracts, but .with the bracts 

 ■sometimes several in a cyme.' Perianth none. Male flowers of 2 sessile anthers 

 anore or less conilate by iheir backs, with 2 parallel Cells opening outwardS'in 



