Nymphales.] 



NYMPH^ACEyE. 



409 



Order CXLVIII. NYMPH^ACE^.— Waterlilies. 



Nymphaacese, Salisburi/, A7in. Bot. 2. p. 6J). (1805) ; DC. Propr. Med. ed. 2, p. 119. (1816) ; S.vst. 2. 

 39. {IS21) ; Frodr. 1. 113. (1824); Wight's Illustrations, p. 24; Endl. Gen. clxxxvii. ; Meisner 

 Gen. 6. 



Diagnosis. — Nymplial Exogens, with a many-celled fruit and dissepimental placenfcB. 



Herbs, with peltate or cordate flesliy leaves, arising from a prostrate trunk, growing 

 in quiet waters. Flowers large, showy, often sweet-scented. Sepals usually 4, free, 

 rarely adherent ; petals nume- 

 rous, imbricated, often passing 

 gi'adually out of the last into 

 stamens ; the former persistent, 

 the latter deciduous, and m- 

 serted upon the disk, sometimes 

 forming a monopetalous corolla. 

 Stamens numerous, inserted 

 above the petals into the disk, 

 filaments petaloid ; anthers 

 adnate, bursting inwards by a 

 double longitudinal cleft. Disk 

 large, fleshy, surroimding the 

 ovary more or less. Ovaiy 

 polyspermous, many - celled, 

 with radiating stigmas, alter- 

 nate with the dissepiments ; 

 ovules numerous, anatropal, 

 attached to the sides of the 

 dissepiments. Fruit many- 

 celled, indehiscent. Seeds very 

 numerous, attached to spongy 

 dissepiments. Albumen farin- 

 aceous. Embryo small, on the 

 outside of the base of the far- 

 inaceous albumen, inclosed in 

 a fleshy vitellus ; cotyledons 

 fleshy, concave; plumule ob- 

 lique. 



The opinions of Botanists 

 are divided concernmg the time 

 nature of the structure of these 

 beautiful plants, and conse- 

 quently as to their proper sta- 

 tion in a Natm'al System. This 

 has been caused by some pe- 

 culiarities in the embryo on the 

 one hand, and by the want of Fig. CCLXXXVll. 



any resemblance m the inter- 

 nal condition of the stem and that of Exogeus. Richard supposed the vitellus, or am- 

 niotic sac, m which the embryo is inclosed, to be a cotyledon, enveloping a two-lobed 

 plumule; and hence the Order was referred to Endogens, or Monocotyledons, and 

 placed in the vicinity of Hydrocharads. But it is now well known that Richard's 

 cotyledon is a vitellus, analogous to that of Peppers, Gingerworts, and others ; and 

 that what Richard and his followers denominated plumule, is a 2-lobed embryo, whence 

 the Order is more generally placed in Exogens, or Dicotyledons. Even Von Martms, 

 who once adhered to the opinion that Waterlilies are monocotyledonous, and nearly 

 related to Hydrocharads, (see Ilortus Rerjkis Monacemis, p. 25.) now places the Order 

 near Crowfoots (see Conspectus, No. 188). Those who are curious to exammc the 

 diflFerent opinions on this subject are referred to De Candolle's Memoir, m the first 

 volume of the Transactions of the Physical and Natural History Society of Geneva. 



Fig. CCLXXXVll.— Nymphaea alba. 1. the pistil ; 2. a perpendicular section of a seed ; 3. half an 

 embryo, showing the great plumule lying in the cavity of one cotyledon. 



