nectarium

The importance of the nectarium or honey-gland in the vegetable economy is seen from the very complicated apparatus, which nature has formed in some flowers for the preservation of their honey from insects, as in the aconites or monkshoods; in other plants instead of a great apparatus for its protection a greater secretion of it is produced that thence a part may be spared to the depredation of insects.

The Botanic Garden A Poem in Two Parts. Part 1: the Economy of Vegetation Erasmus Darwin 1766

This bird much resembles the white-throat, but has a more white or rather silvery breast and belly; is restless and active, like the willow-wrens, and hops from bough to bough, examining every part for food; it also runs up the stems of the crown-imperials, and, putting its head into the bells of those flowers, sips the liquor which stands in the nectarium of each petal.

The Natural History of Selborne, Vol. 2 Gilbert White 1756

They also found growing on the roots of a tree that strange fungus flower described by Sir Stamford Raffles in his book on Java and Sumatra -- a yard wide across the petals, brilliantly coloured red, purple, yellow and white, and, in the hollow of the flower (nectarium), capable of holding twelve pints of water, the whole weighing from fifteen to twenty pounds; for it is a thick fleshy flower, not frail and delicate as one likes a flower to be.

Sketches of Our Life at Sarawak Henriette McDougall 1851