500 



PHANEROGAMS, 



The Nectaries. Wherever pollination is effected by insects, glandular organs 

 are found in the flowers which secrete odoriferous and sapid (generally sweet) 

 juices, or contain them within their delicate cellular tissue from which they are 

 easily sucked out. These juices are included under the term Nectar^ the organs 

 which produce them being the Nectaries. The position, form, and morphological 

 significance of the nectaries are very various, and always stand in immediate 

 relation to the special contrivances for the pollination of the flower by means of 

 insects. The nectaries are often nothing but glandular portions of tissue on the 

 foliar or axial parts of the flower ; very often they project in the form of cushions 

 of more delicate tissue, or take the form of stalked or sessile protuberances ; or 

 whole foliar structures of the perianth, of the androecium, or even of the gynasceum, 

 are transformed into peculiar structures for the secretion and accumulation of 

 the nectar. Since it is quite impossible to treat these organs morphologically in 

 general terms, a few examples may serve to show the student where he will 

 have to look for the nectaries in different flowers. In FrHillaria imperialis the 

 nectaries are shallow excavations on the inner side of the perianth-leaves near their 



Fig. 365.— Flowers with spurred sepals (A) and petals (B, Q; A Biscutella hispida, R np{mediH7n grandtji07-inn, 



C Aquilejiia cuftadensis. 



base, large clear drops of nectar exuding from them ; in ElcLagnus fusca a glan- 

 dular annular cushion on the gamophyllous perianth (Fig. 353 d)\ in Rheum slight 

 glandular protuberances at the base of the stamens (Fig. 360 dr)-, in Nicotiana 

 an annular callosity at the base of the superior ovary ; in the Umbelliferae a fleshy 

 cushion surrounding the bases of the styles united above the inferior ovary 

 (Fig. 352 h h, p. 490) ; in Compositse they are also at the base of the style (Fig. 362). 

 In Citrus, Cohcea scaiidens, Labiatse, and Ericaceae, the nectary appears as a develop- 

 ment of the floral axis or disc in the form of an annular zone beneath the ovary 

 (Figs. 356 d, 359 A^ jv), &c. ; in Cruciferae and Fagopyrum in the form of four or 

 six roundish or club-shaped outgrowths or warts between the filaments, &c. An 

 abortive stamen is converted into a nectary in the Gesneraceee; in Ciiciimis Melo 

 (the melon) the whole androecium is replaced in the female and the gynaeceum in 

 the male flowers by a similar organ. As a rule the nectaries occur deep down 

 among the other parts of the flower ; and when they secrete nectar, it collects at the 

 bottom of the flowers, as in Nicotiana and Labiatas, Frequently, however, special 

 hollow receptacles are constructed for this purpose, as is especially the case with the 

 bag-like appendages of the perianth-leaves (Fig. 365), usually called Spurs. In 



