NEET BIOLOGY

Detailed explanation-1: -sorus, plural sori, in botany, brownish or yellowish cluster of spore-producing structures (sporangia) usually located on the lower surface of fern leaves. A sorus may be protected during development by a scale or flap of tissue called an indusium.

Detailed explanation-2: -Fern Sori. Sori (singular: sorus) are groups of sporangia (singular: sporangium), which contain spores. Sori are usually found on the underside of the blade. Young sori are commonly covered by flaps of protective tissue called indusia (singular: indusium).

Detailed explanation-3: -In Dryopteris sori, a group of sporangia covered with indusium are present along the margin of pinnae or leaflets. In it 2-8 sori are borne on the abaxial surface of the mature fronds (sporophylls). They are situated in two rows at the tips of the veinlets in between the midrib and the margins.

Detailed explanation-4: -Sori contain 10–13 sporangia interspersed with trichomes and are randomly scattered on the lamina. The annulus is oblique; spores appear to be monolete. Figure 11.192.