LXVII.— THE WHITE WATER-LILY. 
Nymphaa alba Linne. 
REAT interest attaches to the Order Ranales^ the tenth among Dicotyledons 
in Engler’s sequence, on account of the varied types of plants which it 
comprises, their many primitive characters, and the relationships they suggest to 
Gymnosperms and to Monocotyledons. It includes plants of all sizes and of all 
climes, many aquatics, but some shrubs adapted to quite dry conditions. The parts 
of the flower may be more or less completely spiral, or acyclic^ hemicyclic, or whorled 
(cyclic) : the primitive polysymmetry may give place in some forms to specialised 
monosymmetry : the perianth may be uniform (homochlamydeous) or diflFerentiated 
into calyx and corolla (heterochlamydeous), and ranges in colour from the primitive 
greens, yellows, and whites to the higher reds, purples, and blues : the stamens are 
generally indefinite in number, but their insertion ranges from the primitively 
hypogynous to more or less complete epigyny ; and the carpels vary from an 
indefinite number, free and arranged spirally, to whorls of some smaller number 
down to five, three, or one, with a certain amount of cohesion. The embryo is in 
most of them small and imbedded in copious fleshy albumen. Among the fifteen 
Families comprised in the Order are the Lactoridaccce, which consists of the one 
species, Lactoris fernandeziana Philippi, confined to the island of Juan Fernandez ; 
the shrubby Calycanthace<e^ including the Allspice and Wintersweet, in which all 
the floral organs are spirally arranged and graduate into one another ; the 
apparently geologically ancient Laurace<e ; the arborescent and perhaps equally 
ancient MagnoliacecC^ in which some botanists see a close approximation to Cycade^e ; 
the Water-lilies ; the Ranunculacea ; and Berberidace^e. 
The Family Nymph^eacea’, though not an extensive one, is cosmopolitan and of 
considerable structural and physiological interest. They are perennial aquatic 
plants, usually with rhizomes imbedded in the mud ; submerged, floating, or rarely 
aerial leaves, orbicular in outline and involute in vernation ; and solitary flowers, 
often large and fragrant. In the perianth various curious modifications of a spiral 
arrangement occur, and the outer green leaves or sepals graduate into petaloid leaves 
and these again into stamens. Petals and stamens are alike inserted on a fleshy 
hypogynous disk which grows up round the numerous carpels more or less 
imbedding and uniting them. There is generally a sessile stigma, consisting of as 
many radiating lines of viscid surface as there are carpels, and the indefinite ovules 
are scattered over the inner surfaces of the carpels, as they are in Butomus. The 
ripe seeds have an unusual structure, there being a minute dicotyledonous embryo 
imbedded in an endosperm filling the embryo-sac, which is in turn imbedded in a 
similar external food-store or perisperm. 
Most completely aquatic plants are glabrous and have leathery leaves with a 
slimy surface. Their petioles and peduncles contain no woody tissue but numerous 
