differentiate between
(a) Bract and bracteole (b) Pulvinus and petiole
(c) Pedicel and peduncle (d) Spike and spadix
(e) Stamen and staminoid (f) Pollen and pollenium
(a) Bract and Bracteolate Bract is a leaf like structure in the axil. i.e., at the base of which flowers are borne. They can be small or scaly, green and coloured and usually single, whereas bracteolate are bract like structures borne on the stalk of a flower.
(b) Pulvinus and Petiole Pulvinus is the leaf base, which is the proximal swollen region with which a leaf is attached to the stem. Petiole is cylindrical or sub-cylindrical stalk which connects the leaf base with the lamina.
(c) Pedicel and Peduncle The stalk of a flower is known as pedicle, whereas the stalk of whole inflorescence is known as peduncle.
(d) Spike and Spadix In spike inflorescence, the flowers are sessile that develop on an elongated peduncle in acropetal succession, e.g.,Adhatoda. The peduncle is non-fleshy. The spadix inflorescence is like spike, but it is covered by one to a few large bracts called spathes, e.g., Colocasia. The peduncle is fleshy and its opical portion is naked, i.e., without flowers.
(e) Stamen and Staminoid The male reproductive organs or microsporophylls of a flower are called stamen. A fully sterile under developed or abrtive stamen is called a staminoid, e.g., Verbascum.
(f) Pollen and Pollinium Microscope of an angiospermic flower is known as pollen. It is haploid, whereas a mass of pollen grains from the same anther constitute the pollinium as in Calotropis.