THE DICTIONARY OF GARDENING, 



NECTARY. A term that has been used in a some- 

 what vague way either (1) to denote any appendage in 

 a flower that does not belong to one of the series of 

 parts recognised by botanists as forming ordinary 

 flowers (e.g., the glands in front of the petals in Par- 

 nassia palustris), without reference to their function 

 and use to the plant, or (2) to indicate that the part so 

 named produces a sweet fluid (see Nectar), which is 

 retained in the cells on its surface, or soaks out 

 through the walls of the cells or through the stomata 

 (see Stoma). which many of the Nectaries possess in 

 their surface layer of cells. The word is now almost 

 restricted to this latter use, and is employed to denote 

 simply the nectariferous character of the part, whatever 

 may be its structure, and whatever the nature of the 

 part of which it is a modification. 



The relation of the sugary secretions to growth is 

 discussed below, and from this relation it must 

 evidently be present frequently in growing tissues. 

 Flowers present conditions that render rapid growth 

 a necessity at certain times, inasmuch as, just before 

 opening, the various parts of the flower increase much 

 in size, and, after fertilisation, the fruits and seeds 

 usually take on rapid growth. Hence, Nectar may be 

 expected to be largely present in flowers. The many 

 careful observations that have been made of late years 

 by botanists in various countries have shown, among 

 other interesting facts connected with the existence 

 of Nectar in plants, that sugar is present in con- 

 siderable amount in the tissues of many flowers in 

 which there is no trace of Nectar on any part of the 

 surface ; and, also, that Nectaries are frequently pre- 

 sent on vegetative organs of plants, e.g., on stipules of 

 Beans, on the small glandular swellings on the leaf- 

 stalks of species of Prunus, and of the Castor-oil plant, 

 and on the secondary leafstalks of various ferns. Since, 

 then, there is a tendency to produce sugar in the 

 flowers, and since the Nectar containing the sugar 

 tends, like other fluids, to soak through the cell- walls, 

 and to appear on the outer surface of the part in which 

 it exists, we can perceive that insects would probably 

 be induced to visit the flowers to collect the Nectar, 

 just as bees visit the stipules of Beans for this purpose. 

 But, in visiting the flowers, the insects are apt to 

 transfer pollen from the anthers of one flower to the 

 stigma of the next of the same kind visited by them, 

 and they thus aid in securing cross-fertilisation ; a re- 

 sult which experiments show to be productive, in many 

 plants, of more numerous seeds, and healthier and 

 stronger seedlings, than follow self-fertilisation. It is 

 thus an advantage to such plants to have frequent 

 insect-visitors at their flowers. In many unisexual 

 flowers, the seeds could not be fertilised in the absence 

 of insects, since they produce pollen unsuited for con- 

 veyance by the wind to the stigma of the male flowers. 

 Thus, the presence of Nectar is advantageous to both 

 flowers and insects ; and there seems good reason to 

 believe that the habit, in insects, of visiting flowers 

 for Nectar, has brought about, in a great degree, the 

 vast diversities of structure and form in both flowers 

 and flower-frequenting insects. It is necessary for the 

 well-being of the plant that the Nectar shall be so 

 placed as to insure that any insect able to reach it 

 shall transfer pollen from the ripe anthers of one flower 

 to the ripe stigma of a flower (usually older) subse- 

 quently visited. Hence arise most of the irregularities 

 and peculiarities in the form and in the position of the 

 various parts of flowers ; some to insure the access of 

 the suitable insects by the right path, and others to 

 prevent the access of visitors that would remove the 

 Nectar without effecting pollination in repayment of the 

 benefit. 



The position of the Nectary or Nectaries in flowers, 

 and the organs of which they are modifications, differ 

 with the kinds of insects for which they arc suited : some 



Nectary continued. 



lie almost on the surface of the flower, e.g., in Carrot, 

 Elder, Ivy, &c. ; but most are situated in the deeper 

 recesses of the flowers. The position of Nectaries is 

 also affected by the fact that exposure to water, in the 

 form of rain or dew, injures the Nectar, and renders it 

 unsuited for attracting insect visitors. Hence, the 

 Nectaries have to be protected against this danger also. 



From the fact that sugar is present in all growing 

 structures of flowers, and that it is most abundant in 

 the receptacle, in the neighbourhood of the ovary, we 

 should expect to find the Nectaries very generally de- 

 veloped in this region ; and such is very often the case. 

 The chief structures that may be modified to form 

 Nectaries are the following: The receptacle often pro- 

 duces Nectar, either over the whole surface (where not 

 occupied by parts of the flower), as in Marsh Marigold 

 (Caltha palustris), or on special outgrowths, forming 

 what is sometimes called the disk; and this latter may 

 form a complete ring between any two successive series 

 of parts, e.g., in the Maples ; or may be broken into 

 portions surrounding the bases of particular organs, e.g., 

 in cruciferous plants, round the bases of the short 

 stamens. Any of the organs of the flower may be 

 modified to form Nectaries in different plants. 



In Poplars, the stigma acts as a Nectary ; in Urn- 

 belliferce, and in many other plants, the Nectary is 

 closely adherent to the base of the style ; in many 

 SolanacecB, it is at the base of the carpels. The stamens 

 may abort, and may be changed into Nectaries, e.g., in 

 Scrophularia, &c., or they may bear nectariferous spurs, 

 as in Ft'ola (see below), or outgrowths from the filament, 

 or from some point of the connective. On the petals 

 and sepals they often appear, usually as small pits on 

 the inner surface, e.g., in Fritillaria, either uncovered, 

 or, as in some species of Buttercups, covered with a small 

 flat scale, behind which the Nectar is formed. In a good 

 many plants, the petals (and less often the sepals) are 

 tubular or spurred, as in Columbine, Hellebore, Aconite, 

 &c., and the inner end of the organ is the Nectary ; but 

 in some (e.g., Violet) the spur merely serves to receive 

 the Nectar. In Viola, one of the petals is thus extended 



nc 



FIG. 662. ANTHER CELLS AND PROCESS OF VIOLA TRICOLOR. 



A, Process of Anther running into spur of Viola tricolor, 

 much magnified ?i c, Nectar Cells, somewhat exaggerated. 



B, Anther and Process as removed from flower a, Anther 

 Cells ; n c, Nectar Cells. 



backwards, and curious appendages (n c, B, Fig. 662) on 

 two anthers pass into the cavity provided, and there 

 secrete a sweetish fluid. Perhaps no flower presents 

 equal advantages with this to the microscopic tyro who 

 would study Nectar cells ; for not only are these large 

 (n c, A, Fig. 662), but they lie on the outside of the 

 process (their protection being derived from the cover- 

 ing afforded by the spur-like petal previously mentioned), 

 and, consequently, the difficulties of section cutting are, 

 in their case, altogether avoided. Much has been written 

 upon the nature of Nectaries in the leading European 

 languages ; but even the enumeration of the principal 

 works would exceed our space, and we shall content our- 

 selves with naming the following books written in Eng- 

 lish or translated from German, which are replete with 

 information on the mutual actions of the plants and 

 insects: H. Miiller's "Fertilisation of Flowers by In- 

 sects " (Clarendon Press, Oxford) ; Lubbock's " British 



