466 LVIII. LYTHRACEZ (HIERN). [ Rotala. 
2. ROTALA, Linn. Mant. 175. 
Calyx campanulate or rarely tubular, usually hemispherical in fruit, 
4- rarely 5-lobed, in one species with intermediate acicular cornua, 
usually not accrescent. Petals as many as calyx-lobes or 0, usually 
minute, obovate, not corrugated in the bud. Stamens 1-5 usually 4, 
not more numerous than the calyx-lobes; filaments filiform. Ovary 
1—4-celled, free, many-ovuled, sessile; style short or long, oe s 
stigma capitate. Capsule 2-4-valved, many-seeded, usually ape 2: 
the calyx-tube ; placenta usually compressed ; seeds numerous; embrye 
straight with short radicle-—Glabrous herbs growing in wet places or 
even in water. Leaves opposite or verticillate, flat; flowers axillary, 
sessile or subsessile, solitary or few together, bibracteate, in R. num- 
mularia (and perhaps in other species) dimorphous. 
Scattered over the Tropics of the whole world. 
Flowers solitary. . 
Calyx whitish, scarious (or sometimes purplish in R. filiformis). 
Capsule 4-valved. 
Calyx tubular, accrescent . . . 
Calyx campanulate, not accrescent 
Capsule 3-valved. 
Flowers pentamerous; leaves more or less whorled . 
Flowers tetramerous ; leaves always opposite. 
Calyx cornuate . eR re ee ee 
Calyx not cornuate. . . 
eens vnrved, cwueas SS 8. 
Calyx rose-coloured, membranous. Stamens 4. (Mirkooa.) 
Leaves opposite. oe 
Petals small; capsule 2-valved . 7. R. fontinalis. | 
Petals large ; capsule 4-valved . ce ee on ee nummer 
EI a ee a ae myriophyllo : 
Flowers 1-4 together . . 10. B. serpiculoies. 
R. elatinoides. 
R. tenella. 
_ R. verticillaris. 
. BR. stagnina. 
1. 
2. 
3 
4, R. decussata. 
é. R. filiformis. 
1. R. elatinoides, Hiern. Annual, ascending, nearly simple, slen- 
der, subterete, rooting at the base, 2-4 in. high. Leaves ovate-oblong, 
decussate, subsessile, the upper ones sessile shorter and cordate OF 
subcordate at base, }—}in. long; lower internodes longer than ard 
leaves. Flowers solitary, subsessile in the axils of upper leaves, e8¢ 
with 2 subulate bracts at base. Calyx at first campanulate, cylindrica! 
and accrescent in fruit, semipellucid, 8-veined, 4-lobed, not cornuate 5 
lobes 4} of the length of the calyx, deltoid or lanceolate, acute- 
Petals 4, oblong, violet or white, marked with reddish midrib, rae 
exceeding the calyx-lobes. Stamens 2 or 4, inserted below middle : 
calyx-tube, about equalling the calyx-tube. Ovary 4-sulcate, 4-celled, 
ovoid, sessile, without hypogynous disk ; style very short, or stigma 
subsessile. Capsule tubular, 4-celled, dehiscing by 4 valves septi- 
fragally, enclosed in the persistent calyx ; placenta slender, tetragon™"» 
seeds concave on one side, convex on the other.—Ammannia olatincides 
DC. Monogr. Lyth. 28, t. iii. B. Ameletia elatinoides, Bl. Mus. Bot. 
ii. 136. 
