The genus is characterised by its tubular 

 very minutely five or six-toothleted or 

 quite entire calyx ; and capsular fruit with 

 a single seed in each of the two cells. Its 

 brilliant flowers do not expand till evening, 

 and fall off about sunrise; so that during 

 the day it loses its brightness, whence its 

 specific name Arbor tristis or Sad-tree. Its 

 flowers are collected for use as a perfume, 

 and also as a dye, but their colour is not 

 permanent. [A. SJ 



NYCTERINIA. A genus of Scrophula- 

 riacea?, of the tribe Gratiolece, and allied to 

 Manidea in its one-celled anthers. The 

 corolla, as in that genus also, has a long 

 slender tube, and a spreading nearly equally 

 five-lobed limb, with entire or bifid lobes; 

 but the lower stamens, inserted much high- 

 er than the others, have small transverse 

 and often abortive anthers. There are 

 about sixteen species, all natives of the 

 Cape Colony, chiefly annuals, with a few 

 perennials or undershrubs, mostly villous 

 and glutinous, drying black like the Lype- 

 rias, but with more entire leaves, and flow- 

 ers in terminal spikes. Two or three spe- 

 cies, especially X. Lychnidea, have been oc- 

 casionally cultivated in our gardens. 



NYMPH.EACEJE. (Water-lilies.) A na- 

 tural order of thalamifloral dicotyledons, 

 belonging to Lindley's nymphal alliance 

 of hypogynous Exogens, and consisting 

 of aquatic plants, with peltate or cordate 

 fleshy leaves, and a rootstock or stem which 

 extends itself into the mud. Sepals usually 

 four, sometimes confounded with the nu- 

 merous petals, and these often passing gra- 

 dually into stamens ; stamens indefinite, in- 

 serted above the petals into the torus, with 

 petaloid filaments, and adnate introrse an- 

 thers, opening by two longitudinal clefts ; 

 torus large, fleshy, surrounding the ovary, 

 which is many-celled, many-seeded, with ra- 

 diating stigmas. Fruit many-celled, inde- 

 hiscent ; seeds very numerous, attached to 

 spongy dissepiments. The plants of this 

 order are found throughout the northern 

 hemisphere, and are generally rare in the 

 southern. Little is known in regard to 

 their properties. Some are astringent or 

 bitter, while others are said to be sedative. 

 They have showy flowers, and their petioles 

 and peduncles contain numerous air-tubes. 

 Victoria regia is one of the largest known 

 aquatics. It is found in the waters of 

 South America, and is said to range over 

 thirty-five degrees of longitude. There are 

 five genera (e.g. Nymphcea, Victoria, Nw- 

 phar), and about sixty species. [J. H. B.] 



NYMPHS A. The technical name of the 

 genus to which the White "Water-lily of 

 our streams belongs. It constitutes the 

 type of the Nymphceacece, and consists of 

 water-plants, found in lakes or rivers al- 

 most all over the world. They have a fleshy 

 or tuberous rootstock, sending down root- 

 lets into the mud, and throwing up leaves 

 and flowers. The leaves are usually some- 

 what circular in outline, entire or toothed, 

 the veins on the under-surface either pro- 

 minent or depressed ; they float on the 



[ surface of the water, but after a time are 

 partially raised from it ; the leafstalks are 

 cylindrical, traversed with air-canals,which 

 are arranged in a regular manner. The 

 flowerstalks are like the leafstalks in ap- 

 pearance, and like them are permeated by 

 air-canals, which in some instances are 

 arranged in the same manner as those in 

 the leafstalk, in others are disposed differ- 

 ently. The leaf and flower-stalks vary in 

 length according to the depth of the water 

 in which the plant is growing. The flower 

 is placed on the end of the stalk, and con- 

 sists of a calyx with four sepals, green on 

 the outside but petal-like on the inner sur- 

 face, falling off as the fruit ripens ; the 

 petals are numerous, arranged in several 

 rows upon the prolonged receptacle, the 

 inner ones passing by insensible gradations 

 into the stamens, which are likewise very 

 numerous— the outer ones petaloid, the 

 inner linear with their stalks not exceed- 

 ing the anthers in breadth. The ovary is 

 imbedded within the receptacle, on which 

 the outer portions of the flower areinsert- 



| ed ; internally it is divided into numerous 

 many-seeded compartments.and surmount- 

 ed by a plate-like stigma with several di- 

 verging rays, and a depressed centre, oc- 

 cupied by a small conical or ovate body. 



i When ripe the fruit sinks towards the 

 bottom of the water, and rots, and thus 



j liberates the seeds. 



The flowers vary in form and colour in 



f the different species, as also do the leaves. 

 The best-known, and by no means the least 

 beautiful, of these eminently beautiful 

 plants, is the common White Water-lily, 

 A T . alba, pretty generally distributed over 



I Great Britain, but found also in other parts 

 of Europe, and in Northern and Central 

 Asia. No flowers show better the transi- 

 tion from petals to stamens than those of 

 the White Water-lily, and they are also in- 

 teresting from their power of collapsing 

 their petals, and of drooping on to the sur- 

 face of the water, or even sinking below 

 its surface during the night, emerging and 

 expanding again in the sunlight. This pe- 

 culiarity is also noticed in several of the 

 foreign kinds, as in the Egyptian JS r . Lotus, 

 of which Moore, in ' Paradise and the Peri,' 

 thus sings :— 



Those virgin lilies, all the night 



Bathing their beauties in the lake 

 That they may rise more fresh and bright 

 When their beloved sun 's awake. 

 The rootstocks of N. alba are said to be 

 used for dyeing purposes, as they contain 

 gallic acid, and also a large quantity of 

 starch. In Prance they are used in the 

 preparatiou of a kind of beer. Numerous 

 species are cultivated in this country, some 

 of which deserve notice, such as N.odnrata 

 and the small variety of it, N. odorata minor. 

 These are North American, and resemble 

 our European species. N. scutifolia and 

 J\ T . ccerulea have fragrant blue flowers ; the 

 latter is the Blue Lotus of the Nile, and is 

 generally met with in English gardens 

 under the erroneous name N. cyanea. One 

 of its varieties, and also another species 

 called N. micrantha, or N. guineensis, are 



