The narrowly oblanceolate to oblong leaf of Drosera hilaris has a prominent covering of gland-tipped hairs, but only on the leaf blades, not the petioles. A leaf may become 7 cm long with pale, fringed stipules at the base of the leaf stalk.
The leaf in picture shows the glands at the tips of the long, sparsely scattered red hairs, more densely covering the leaf margins than the central part. There are rusty hairs on the lower leaf surface as well. The yellowish green leaf surface seen at this angle hides the red hairs behind the glands in the leaf centre; still, they are present, sparsely distributed.
The sticky fluid secreted by the glands on the leaf hairs visibly envelops some of the glands themselves in the photo, rendering them more globular than they may really be.
The function of this secretion is also visible here: several hapless small insects are caught upon the leaf surface. They cannot escape and will be consumed where they sit within a few hours at most, broken down chemically, digested and absorbed by the plant.
A Drosera plant doesn’t use its roots much for acquiring nutrients, being endowed with this convenient aerial shortcut for receiving its daily bread. There are usually two kinds of glands on Drosera leaves: firstly stalked ones that ensnare through the offering of sweetness concealing the digestive enzymes lurking in the juice as well, assisted by the neighbouring tentacles bending over to have more sticky glands touching (and securing) the victim, and secondly sessile glands on the leaf surface that absorb the insect soup dished up by the enzymes. The system appears efficient with little or no leftovers to be discarded (or recycled) (Bean and Johns, 2005; Bond and Goldblatt, 1984; iSpot).
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