Triglochin.| CLIII. NAIADACE (BENNETT), 215 
Orver CLIII. NAIADACEH. (By Arthur Bennett.) 
Flowers usually green (often coloured in Aponogeton), 1—2-sexual. 
Perianth 0, or tubular, or of 3-4 inferior valvate segments. Stamens 
hypogynous; anthers 1-2-celled, Ovary of 1-4 1-ovuled carpels ; style 
long or short; stigma of many forms. Fruit of 1-seeded utricules, 
achenes, or drupelets. Seeds exalbuminous; embryocurved or straight, 
large at the radicular end.—Aquatic or marsh herbs, of various habit. 
Rootstock usually creeping. Stems simple or branched. Leaves erect, 
submerged, or floating, sheathing at the base; stipules 0, or contained 
in the sheath. . 
Genera 16, species about 120, found in all climates. 
*Stigmas discoid or decurrent on the ovary. 
Perianth present ; flowers bisexual. 
Marsh herbs ; sepals 6, green : = . 1. TRIGLOCHIN, 
Aquatics. 
Sepals 1-3, white or coloured. : . 2, APONOGETON. 
Sepals 4, herbaceous . i ; » 3. POTAMOGETON. 
Perianth none ; flowers uni- or bi-sexual. 
Stamens 2; carpels stipitate . A . 4, RUPPIA. 
Stamen 1; carpels usually sessile 5, ZANNICHELLIA. 
**Stigmas subulate or capillary. 
Flowers sessile on a flat linear spadix . 6. ZOSTERA. 
Flowers axillary , : é : H é ccs NATAS. 
Flowers enclosed in membranous sheaths 8. CYMODOCEA,. 
1, TRIGLOCHIN, Linn. ; Benth. et Hook. f. Gen. Pl, iii. 1012. 
Perianth-segments 3 or 6, herbaceous, deciduous. Stamens 6, at the 
base of the perianth-segments; anthers with 2 rounded lobes. Carpels 
3-6, 1-celled, l-ovuled, 3 often imperfect; styles short, sometimes 
connate ; stigmas sessile or subsessile, plumose. Fruit of 3 or 6 free 
or connate achenes or follicles; tips recurved. Seed erect; embryo 
straight.—Marsh herbs with rush-like flat or terete leaves. Flowers 
small, bisexual, spicate or racemose, 2-bracteate. 
Species about 12, chiefly in the temperate regions of both hemispheres. 
Fruit linear . : ; > ; ‘ - Bs aed 1 bulbosum. 
Fruit subrotund . ° ‘ > ‘ ‘ . 2. 7. striatum, 
1. T. bulbosum, Linn. Mant. Alt. 226. Stem simple, tuberous 
at the base, with interlaced fibres forming a brown mass at the base. 
Leaves half-cylindrical, finely striate, channelled, generally shorter than 
the stem. Raceme elongating after flowering, 6—12-flowered. Fruits 
erect, ascending (not adpressed), larger at the base than the apex, of 
3 carpels.— Bot. Mag. t. 1445; Micheli in DC. Monogr. Phan, iii. 99; 
Buchen. in Engl. Jahrb. ii. 510; Durand & Schinz, Conspect. Fl. Afr. v. 
