124 SPARGANIACEAE. [Sparganium. 
into a long but rather narrow sheath. Inflorescence simple in small speci- 
mens, but usually with 1-3 slender flexuous branches bearing male heads 
alone or very rarely with a single female below the males; main rhachis 
with 2-4 distant female heads below, and 3-12 more closely placed male 
ones above; the lower portion of the inflorescence with long leafy bracts. 
Filaments of the male flowers long, considerably more than twice the length 
of the scales. Stigma narrow, elongate. Ripe fruit about $m. long, broadly 
obovoid, mucronate with the short thick persistent style—Cheesem. Man. 
N.Z. Fl. (1906) 744; Ill. N.Z. Fl. 1 (1914) t. 205. 8. angustifoliam R. Br, 
Prodr. (1810) 338 (not of Michx.); Benth. Fl. Austral. vu (1878) 160; Col. 
in Trans. N.Z. Inst. xvi (1884) 339. 8. simplex Hook. f. Fl. Nov. Zel. i 
(1853) 238; Handb. N.Z. Fl. (1864) 277 (not of Huds.). 
Nort Istanp: Watery places from the North Cape to Wellington, not uncommon. 
SourH Istanp: Near Picton, J. Rutland! swamps at Methven, Canterbury, Dr. Gaze 
Maru. December—March. 
Also in Australia, from Queensland to Victoria. S. subglobosum Morong in Bull. 
Torrey Club, xv (1888) 76, t. 79, f. 1, said to have been collected at the Bay of Islands 
by the American Exploring Expedition, is probably the same, and, if so, Morong’s name 
will take precedence. =e Jk cla. 4 4 Se. D4 Sav 
Family XI. NAIDACEAE, “*=**- 
Submerged or floating fresh-water or marine aquatic plants, or marsh 
herbs. Stems often elongated, slender, branched, jointed ; sometimes short 
and almost wanting. Leaves very various, altogether submerged and 
translucent, or floating and opaque, or all radical, sheathing at the base ; 
stipules wanting or interpetiolar, connate and sheathing. Flowers small 
and inconspicuous, usually green, hermaphrodite or unisexual, variously 
arranged. Perianth either wanting, or of 3-6 inferior segments valvate 
in bud. Stamens 1-6, hypogynous; anthers basifixed, erect, 1—2-celled. 
Ovary superior, of 1-6 distinct or more or less connate carpels, each 1-celled 
with usually a single erect or pendulous ovule; style. long or short, stigma 
various. Fruit of 1-6 indehiscent nutlets or utricles, rarely drupaceous. 
Seed solitary, testa membranous; albumen wanting; embryo straight or 
curved, radicle unusually large. 
A small family, dispersed over the whole world in marshy places, ponds, lakes, 
rivers, &c., also including some widely spread marine plants. Genera 16, species 
estimated at 120. The order cannot be said to have any important properties or uses. 
With the exception of Lepilaena, which is found elsewhere in Australia alone, all the 
New Zealand genera have a wide range in both temperate and tropical climates. The 
Naiadaceae are now frequently broken up into three or four families, but in a small 
flora like that of New Zealand it seems undesirable to multiply such divisions. 
A. Flowers hermaphrodite. Perianth of 4-6 herbaceous segments. 
Marsh plants with linear radical leaves. Flowers on erect scapes. 
Perianth-segments 6 4 2 sae - .. Ll. TRIGLOCHIN. 
Aquatic plants with submerged or floating stems and leaves. 
Flowers in axillary or terminal spikes. Perianth-segments 4.. 2. POTAMOGETON. 
B. Flowers unisexual (except in Ruppia). Perianth wanting or minute and hyaline. 
* Stems and leaves filiform, submerged. 
Blowers hermaphrodite, 2 or 3 on a peduncle greatly elongating 
in fruit. Perianth wanting. Stamens 2; anthers ‘almost 
sessile. . 7 as = 2 Ks .. 9 RUPPIA. 
Flowers unisexual, axillary, nearly sessile. Perianth wanting or 
female small and hyaline. Stamen 1, filament slender .. 4, ZANNICHELLIA. 
