1014 CXCV. NAIADACEJE, [ Aponogetonec. 
(seapo apice 2-cruri) 2-nze, ad apicem scapi sessiles, prima j tute spatha extinctoriformi 
v. fissa hyalina caduca incluse. — Flores in rhachin spicee unilaterales et distichi, v. poly- 
stichi et undique rhachi inserti, perianthii segmentis (bracteisve) amplis albis v. rarius 
roseis aut violaceis. 
Species ad 20, Asie et Africee tropieze et temperat:e Australieque incole. Planeh. in Ann. Se. Nat. 
Ser. 3, i, 107. Benth. FI. Austral, vii. 188. Baker in Trans. Linn. Soc, xxix. 158, et in Journ. Linn. 
Soc. xviii. 279. —.Roxb. Cor. Pl. t. 81.  Edgew. im Hook, Lond. Journ. ii. 1.17; et (. 18 (Ouvi- 
randra). Bot. Mag. t. 1268, 1293, 6399. j 
OvvigaxDRA, Thow. Gen. Nov. Madag. 2 (HxvpmookTON, Pers. Syn. i. 400) ab Aponogetone 
nullo charactere differt nisi defectu parenchymatis inter nervos folii, — Deless. Jc. Sel. iii. (. 99, 100. 
Bot. Mag. t. 4894, 5076 (ic. in. FI. des Serres, t. 1107-8, 1491-2, dterate). Ill. Hortic. (. 300. Regel, 
Gartenfl. t. 387. Edgeworth, in Hook. Lond. Journ. iii. 402, distinguit Aponogetonem ab Quvirandra. 
(char. reform.) evolutione embryonis, ledone in priore sub germinatione elongata plumulam tardius 
€ basi latere evolvente; in posteriore plumula magna 2-folia in sinu elongato embryonis latet. Nos 
enim sectiones tres Aponogetonis ad indolem seminis distinguere possumus sed nullis aliis charac- 
teribus eongruentes: l. Testa carnosula v. subcorjacea, embryope oblongo v. lanceolato ventre 
excavato, plumula simpliei in fissura abseondita ; includit A. elongatum, F. Muell., A. spat E. 
Mey.,aliosque. 2. Testa carnosula, embryone oblongo, plumula sinui ventrali imposita valde evoluta 
2-poly-phylla; includit, 4. crispum, Thunb., 4. fenestralem, Hook. £, 4. Bernerianum, Hook. f., 4. 
undulatum, Roxb., aliosque. 3. Seminum integumentum duplex, exterius laxum hyalinum et longitudi- 
naliter plicatum, interius coriaceum, brunneum, embryone cylind obtuso homog germina- 
tione in cornu elongato, plumula basin versus cornu tarde evoluta ; includit 4, monostachyum, Linn. 
f. A. distach "Thunb., A. val/isnerioidem, Baker, aliosque. 
TRrsus III. PorAMEX. 
6. Potamogeton, Linn. Gen. n. 174.—Flores hermaphroditi, spieati. Perianthii seg- 
menta 4, rotundata, brevissi iculata, concava, herbacea, sestivatione valvata. 
Stamina 4, unguibus segmentorum inserta; anthers sessiles, didym:e, loculis connectivo 
crassiusculo v. tenui sejunctis lateraliter dehiscentibus. Ovarii carpella 4, sessilia, 
distincta, l-locularia, in stylum brevem v. brevissimum attenuata, stigmate peltato v. 
stylo apice introrsum stigmatoso ; ovula solitaria, medio v. supra medium anguli interioris 
carpelli ventre v. apice affixa, campylotropa, micropyle infera. Carpella matura 4, parva, 
ovoidea v. subglobosa, obtusa v. sti, recurvis apice uncinata, 1-sperma, pericarpio 
crasse coriaceo spongioso v. indurato, issi b Semen ii 
hilo ventrali v. subapicali, testa b ; embryo d tremitate coty- 
ledonari attenuata uncinata v. involuta, plumula inclusa.— Herbs» aquatice, rhizomate 
repente, ramis dichtomis demersis teretibus v. compressis. Folia distiche alterna v. 
rarissime opposita, demersa membranacea, emersa natantia, membranacea v. coriacea ; 
stipule intrafoliacere, ligulatze, liberse v. basi folii v. petioli adnate. Pedunculi axillares, 
emersi, basi spatha membranacea stipati. Flores parvi, vi tes v. ruf. bracteati 
et ebracteolati. 
n" 1 ;otatil 
Species ad 50, cum ;ipeci e is quarum mults pro speciebus auctoribus 
variis habite, Kwnth, Emum. Pl. ii. 127. Hobbins im A. Gray, Man. Bot. N. U. St, ed, v. A84. 
Walp. Ann.i. 766, ii. 504. Benth. Fl. Austral. vii. 169. Gertn. Fruct. ii. t- 84. JMirb.in Ann. 
Mus. Par. xv. 1.18; L. C. Rich. ibid. xvii. t. 5, f. 31 ad 31. Nes, Gen. Fl. Germ, Monocot. iii. n. 48. 
Sehnizl. Iconog. t. 71. Reichb. Iconogr. Bot. t. 175,176, 184, 185; Ic. Fl. Germ, t. 18 ad 00. Cosson, 
Atlas, ed. 2, 1. 35 ad 37. — Ruiz et Pav. Fl. Per. et Chil. t. 106. Haoul, Fl. Nov. Zel. t. 7. 
Srnnizuus, J. Gay in. Comptes. Hend. Acad. Sc. April, 184, genus ad. P. hybridum, Mich. (P. 
Spirillum, Tuckerm.), conditum floribus 9 solitariis sübmersis unacum emersis spieatis hermaphroditis, 
periearpio membranaceo, embryone involuto et. rhizomate continuo (nee sympodiali). 
GnoENLANDIA, J. Gay l.c. ad P. densum, L., condita, a congeneribus plerisque differt, pericarpio 
membranaceo, et embryone apice cireumvoluto. 
Pxrrorsis, Fafin. Journ, Phys. lxxxix. 101, genus ad P. perfoliatum stabilitum fuit. 
7. Ruppia, Linn. Gen. n. 175.— Flores hermaphroditi, spicati. Perianthium 0. 
Stamina 2, opposita (v. 4 antheris 1-locularibus), fil iis breyissimis latis ; antherse 
