Hydrilla.] CXLVI. HYDROCHAKIDE^;. (J. D. Hooker.) 659 



Flowers unisexual, solitary. Fruit winged 6. OTTELIA. 



Flowers unisexual. Male spathes many-fld. Ovary stoutly 



beaked 7. BOOTTIA. 



Tribe IV. Thalassieae. Salt-water herbs. Spathes 2-leaved. Ovary 

 beaked in all. 



Male spathes many-fld. Perianth double 8. ENHALTJS. 



Male spathes 1-fld. Perianth single 9. HALOPHILA. 



1. HVDRXXiXiA, Richard. 



A submerged leafy dioecious herb. Leaves short, 3-4-nately whorled, 

 or the lower opposite. Male fl. solitary, shortly pedicelled, in a subglobose 

 sessile muricate spathe ; sepals 3, ovate or obovate, green ; petals 3, oblong 

 or cuneiform ; stamens 3, anthers large reniform, opening elastically ; 

 pistillode small. Fern. fl. 1-2, sessile in a tubular 2-toothed spathe ; 

 perianth of the male, but leaflets narrower ; ovary produced beyond the 

 spathe in a filiform beak, 1-celled ; styles 2-3, linear, undivided ; stigmas 3, 

 fimbriate ; ovules anatropous. Fruit subulate, smooth or muricate ; seeds 

 2-3, oblong, testa shortly produced at each end. 



K. verticillata, Gasp, in Monatsber. AJcad. Berl. 1857 ; Pringhs. 

 Jahrb. i. 493 ; Boiss. Fl. Orient, v. 8 ; Benth. Fl. Austral, vi. 259. H. 

 ovalifolia, Rich, in Mem. List. Fr. 1811, ii. 76, t. 2 ; Thwaites Enurn. 331 ; 

 DaU.Sf Gibs. Bomb. Fl. 377. H. dentata, Gasp, in Bot. Zeit. 1854, 56. 

 H. Wightii, Planch, in Ann. Sc. Nat. Ser. 3, xi. 79. H. angustifolia, Blume 

 Mus. Bot. \. 82. Leptanthes verticillata, Herb. Wight. Serpicula verti- 

 cillata. Linn.f. Suppl.416; Roxl. Fl. Ind. iii. 578; Cor. PI. ii. t. 164 ; 

 Wall. Cat. 5048. Vallisneria verticillata, Roacb. Fl. Ind. iii. 751. Hot- 

 tonia serrata, Willd. Sp. PL i. 816. 



Still and slowly running waters throughout INDIA and CEYLON. DISTIUB. 

 Central Europe, Mauritius, Madagascar, Tropical Asia and Australia. ^ 



Plants forming large masses. Leaves % in., 4-8 in a whorl, with a short 

 sheathing one at the base of each branch and a short pair above this, linear or 

 oblong-linear, serrulate or entire. Flowers i-i in. long; perianth segments very 

 variable. Fruit smooth or sometimes muricate or (in Ceylon, Thwaites) squarrose 

 with filaments above the middle. The male fl. escape from the sheath when mature, 

 and float on the top of the water. 



2. XiAG-AROSXPHON, Harr. 



Submerged dioecious herbs. Leaves scattered, fascicled or subwhorled, 

 lower opposite, serrulate. Malefl, minute, many in an ovoid 2-fid axillary 

 sessile spathe ; sepals petaloid ; petals rather shorter ; anthers 2 or 3, ovoid, 

 with often 3 staminodes ; pistillode 0. Fern. fl. solitary, sessile in a narrow 

 oblong spathe ; perianth of the male ; staminodes ; ovary oblong, produced 

 into a filiform beak ; styles 3, stout, notched ; ovules many, orthotropous. 

 Fruit ovoid, oblong or linear, many-seeded. Species 5, India, Africa, and 

 Madagascar. 



Zi. Roxburgh!!, Benth. in Gen. PL iii. 451 ; leaves 2-4 in. scattered 

 linear-lanceolate. Nechamandra alternifolia, Thivaites Enum. 332. N. 

 Roxburghii, Planch., in Ann. Sc. Nat. Ser. 3, xi. 78 (excl. syn. Roxb. Cor. 

 PL) ; Dalz. $ Gibs. Bomb. FL 277. Vallisneria alternifolia,.Boa?6 Fl. Ind. 



