What are nectaries? What are the types of nectaries?

Nectaries are exocrine tissues of plants that secrete sugar solutions. Its shape, size, color and location vary with different plant species. Nectaries usually consist of one or several layers of secretory cell groups, or are specialized by epidermal cells.

According to the different organs where nectaries are distributed in plants, they can be divided into floral nectaries and extrafloral nectaries.

(1) Flower nectary (Figure 53). Refers to nectaries distributed in flower organs or inflorescence components. Common positions are: located at the base of perianth, on or on calyx, within the base of petals, within a distance, between calyx or corolla and stamen, on or between stamen base and ovary, on the base of ovary, on the inner periphery of flower tube, on the top of ovary around the base of style, on the lower ring of stigma, on ovary diaphragm, bud piece, flower stalk and flower.

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Fig. 53 nectaries in rape flowers

(2) Extrafloral nectaries (Figure 54). Refers to nectaries distributed on vegetative organs such as young stems or leaves (leaves, petioles or stipules). Extrafloral nectaries on leaves are common, such as nectaries on veins, leaf margins, petioles and stipules.

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Fig. 54 nectaries of cotton veins