430 



THE DICTIONARY OF GARDENING, 



Nectary continued. 



sary in regard to the use of sugar to plants. There is 

 reason to believe that sugar is one form in which part 

 of the food, formed by plants for themselves from that 

 taken in by them, is retained for a short time in a state 

 that is readily available for use in forming new cell-walls 

 in growing organs, or other substances of the same 

 general composition. Wherever growth is active, sugar 

 is present in the tissues, and gives its characteristic 

 results when tested for. Hence, sugar is present, one 

 may say, in the tissues of all flowers, whatever the mode 

 of their fertilisation ; but in some, the sugar is retained 

 in the tissues, while in others it is contained in the sur- 

 face cells, or oozes out on the surface of certain parts 

 called Nectaries, which serve as the attraction to insects. 

 Besides floral Nectaries, or those in the flowers, there are 

 also in some plants (e.g., in some Ferns and in the common 

 Bean) extra floral Nectaries. In the Bean, they are on the 

 stipules, and form a great attraction to bees in the search 

 for honey. In the Bracken Fern (Pteris aquilina), the 

 Nectar flows from small, pale swellings at the bases of the 

 secondary petioles. It has been found that emission of 

 water vapour into the atmosphere, and emission of Nectar 

 on the surface of the Nectary, are so related that what 

 favours the one, retards the other. In the flowers, it is 

 usually emitted most abundantly in the early morning, 

 diminishes till afternoon, and again increases towards 

 evening. It is generally found to be more abundant in 

 flowers of the same kind, the colder the climate. 



The position of the Nectary (n, B, Fig. 663) now 

 demands attention. It lies above the anthers and 

 stigmas, and an insect, in seeking sweets, would insert 

 the tongue with the body in such a position that its 

 hairs would dust off the pollen, or else rub against the 

 stigmatic faces. It may be observed, in a Pelargonium 

 truss, that recently-opened blossoms have their anthers 



FIG. 667. A, BEE GATHERING NECTAR FROM RASPBERRY BLOS- 

 SOM A, Anther ; S, Stigma ; C, Nectary Opening ; P, Petal ; 

 D, Drupel. B, SECTION THROUGH RIPE FRUIT, showing Fer- 

 tilised and Unfertilised Drupels A', Withered Anthers; D, 

 Drupels. 



already shedding their pollen, while the stigmatic faces 

 are held firmly in mutual contact, so that fertilisation 

 is impossible ; but that older blossoms, from which the 

 pollen has all, or nearly all, disappeared, have their 

 stigmatic surfaces exposed, since they have separated 

 and curled back upon the top of the style, as at , C, 

 Fig. 663 clearly pointing to an effort to secure cross- 

 fertilisation. If an insect visits a young flower with 

 stigmas not yet receptive, it nevertheless secures 

 pollen on its breast, which it transfers to the stigmas of 

 older flowers, when seeking their Nectar. 



The enormous importance of insects' visits has not, 



Nectary continued. 



until recently, been realised. See Hybridising To 

 mention only a few instances, our orchard and fruit 

 crops, and leguminous seeds, forming together no in- 

 considerable fraction of human food, are very largely 

 dependent upon insect agency, and the fee paid for 

 professional attendance on the part of the insect inocu- 

 lator, is Nectar. Let us take, as an illustration, a 

 common Easpberry. The nectar glands have their tiny 

 openings (C, Fig. 667) set in a ring just within the very 

 numerous anther filaments. The stigmas (S) of the various 

 drupels (D) need the pollen to be passed from the 

 anthers (A) to the surfaces of the former, but the in- 

 terval between the two is considerable. A bee settles, 

 and, in applying her tongue consecutively to the cir- 

 cularly-disposed sources of supply, makes a revolution. 

 The side of the body is thus dusted with pollen; but 

 this is not transferred to the stigmas. Flitting to a 

 neighbouring blossom, she generally revolves the body 

 in the opposite direction, so as to rest the legs pre- 

 viously most exercised, and so transfers the pollen before 

 gathered to the waiting stigmas, thus securing cross- 

 fertilisation. If the stigmas be not in this way pollinated, 

 the drupels do not develop, and we get, on part of the 

 Easpberry, shrunken greenish-grey abortions, of which 

 two are seen in the section. These failures are common 

 late in the season, in consequence of imperfect insect 

 action. 



NECTRIS AQUATICA. A synonym of Cabomba 

 aquatica (which see). 



NEEDLE FURZE. See Genista anglica. 



NEG-UNDO (said to be a native Asiatic name). Box 

 Elder. ORD. Sapindacece. A small genus (four species) 

 of hardy trees, allied to Acer; they are natives of 

 temperate North America and Japan. Flowers dioecious, 

 small, long-stalked, pendulous, unfolding before the leaves ; 

 the males cymose-fasciculate, the females racemose and 

 shortly pedicellate. Leaves opposite, pinnately three to 

 five-foliolate ; leaflets petiolulate, induplicate in vernation. 

 For culture, see Acer. 



N. aceroides (Maple-like).* jl. green, dioecious ; males in 

 fascicles, on filiform pedicels ; females in racemes ; petals absent. 

 Spring. I. pinnate, with three to five opposite, coarsely and 

 deeply toothed leaflets, with the odd one usually th 



h. 40ft. North America, 

 . fraxinifolium. 



ree-lobed. 

 A very ornamental tree. SYN. 



N. a. crispnm (curled). A form having its leaves variously cut 

 and curled, but not nearly so vigorous as the type. 



N. a. laciniatum (laciniated). I. more deeply cut than those 

 of F. a. 

 species. 



crispum. This is also less vigorous than the typical 

 A handsome variegated-leaved 



N. a. variegatum (variegated). 



kind. 

 N. Cissifolium (Cissus-leaved). I. trifoliolate, small, light green. 



h. 5ft to 10ft. Japan. An elegant small species. SYN. Acer 



cissifolium. 



N. fraxinifolium (Ash-leaved). A synonym of JV. aceroides. 

 N. nikoenso (Niko). I trifoliolate, shortly stalked, the petioles 



and under surfaces of which, as well as the shoots, the buds, and 



the cells of the large fruits, are very hairy. Japan, 1881. A most 



distinct species. 



NEILLIA (named after Patrick Neill, of Edinburgh, 

 secretary of the Caledonian Horticultural Society, in the 

 early part of this century). SYN. Adenilenia. ORD. 

 Rosacece. A genus comprising four or five species of 

 hardy branching shrubs, inhabiting Northern India and 

 Java, Manchuria, and North America. Flowers white, 

 racemose or paniculate, rather large; calyx persistent; 

 tube campanulate or broadly turbinate. Leaves simple, 

 variously lobed and toothed. The species here described 

 are probably the only ones introduced. They form ex- 

 cellent plants for shrubberies; the two last-named, 

 however, require a little protection in winter. Almost 

 any soil will suit them, and propagation is effected by 



