412 



NATURAL HISTORY OF PLANTS. 



Ammannia (Rotala) vcrticillaris. 



portula, but has generally a tctramerous and tetrandrous flower. 1 

 The true Ammannias, more confined to the warm regions of both 

 worlds, often have the tctramerous flower of Didiplis, with or without 

 petals and with the accessory teeth of the calyx more or less deve- 

 loped. In some cases the flower has 

 as many as seven parts ; in others 

 again, there are only three, as in 

 Rotala 2 (fig. 423, 424). The length 

 of the style varies much also between 

 one species and another. The stamens 

 may be the same in number as the 

 sepals or double, or even less in num- 

 ber. Suffrenia (fig. 420-422), like 

 Didiplis, may have only two stamens ; 

 and the petals, when they exist, are 

 either very small or moderately de- 

 veloped. The dry fruit may open regularly, like every septicidal or 

 septifragal capsule : this is the case in Rotala, Saffrenia, and Ame- 

 letia ; 3 but it may also open transversely or irregularly, as in 

 Didiplis and Cryptotheca? It is on these variations that the three 5 

 sections we admit in the genus Ammannia are founded. This genus 

 comprises about thirty-five species, 6 annuals or evergreens, often 

 aquatic, with opposite or verticillate, rarely alternate leaves, axillary 

 solitary flowers, accompanied by lateral bracteoles which are fertile 

 when the flowers are collected in cymes or few-flowered glonie- 

 rules. 



Fig. 423. Flower (i). 



Fig. 424. Long. 

 6ect. of flower. 



1 It may lie diandrous. The sepals are some- 

 times five or six in number. The petals are 

 wanting, as is often the case in Peplis Portula, 

 and the accessory teeth of the calyx are as 

 marked as in the latter. 



2 L. Mantiss. 175.— DC. Prodr. iii. 75.— A. 

 S.-H. Mêm. Mus. ii. 381.— Endl. Gen. n. 6143. 

 — ? Ortegioidcs Soland. (ex Endl.). — Entelia 

 Ii. Be. (ex Endl.). — Tritheca Wight and Akn. 

 Prodr. i. 305. 



3 DC. Mêm. Genèv. iii. p. ii. 82, t. 3 ; Prodr. 

 iii. 76. — Endl. Gen. n. 6145. — Ditheca Wight 

 and Ahn. Prodr. i. 304. — Sapalocarpum Wight 

 and Akn. loc. cit. 305. — Amanella Mm. Fl. Ind.- 

 Bat. i. p. i. 618. 



* Bl. Bydr. 1128.— DO. Prodr. iii. 76.— Endl. 

 Gen. n. 6141. 

 5 Bentham and Hooker admit two : one in 



which the flowers are pedicellate with capsule 

 opening transversely or irregularly ; the other 

 in which the flowers are solitary, sessile, with a 

 valvicide fruit. We add a third section Peplis 

 (including Didiplis). 



6 Eoxb. PI. Corom. t. 133.— Bl. Mm. Lugd.- 

 Bat. ii. 129, t. 44 (Cryptotfieea), 135, t. 46, 47 ; 

 136 (Rotala). — Ledee. Ic. Fl. Moss. t. 391 

 (Peplis). — Wight, Madr. Journ. So. vii. 312, t. 

 20 (Nimmoia) ; Peon. t. 217, 260 (Rotala).— 

 Both, Nov. Sp. 162 (Sellowia). — Spkeng. S>/st. 

 i. 519 (Winterlia). — Bellakd. Act. Taut: vii. 

 445, t. 1. fig. 1 (Sufrenia).— Habv. Thes. Cap. 

 ii. t. 189 (Suffrenia). — Hahv. and Sond. Fl. Cap. 

 ii. 515.— Griseb. Fl.Bnt. W.-Ind. 270.— Thw. 

 Eimm. PI. Zeijl. 121, 122 (Ameletia, Rotala).— 

 Mm. Fl. Ind.-Bat. i. p. i. 614 (Tritheca, Rotala), 

 015 (Ditheca, Suffrenia), 616 (Ameletia), 617 



