AP BIOLOGY

Detailed explanation-1: -Noun. coenosorus (plural coenosori) (botany) A compound sorus consisting of multiple fused sori.

Detailed explanation-2: -A continuous line of sporangia. It is seen in certain ferns, e.g. Pteridium, where discrete sori are not produced.

Detailed explanation-3: -The underground stem is branched and perennial, rhizomatous and surrounded with brown scales. A few of the species display lasting leaf bases on their rhizomes. Leaves arise from the upper portion of the rhizome having a long rachis. The Petiole base is sometimes covered with brown scales and other times with ramenta.

Detailed explanation-4: -Pteris-External Morphology The Petiole base is sometimes covered with ramenta and some other times covered with brown scales. Leaves are unipinnate compounds, microphyllous, arising in an acropetal pattern on the rhizome. The Bipinnate leaves, digitate and decompound leaves are also observed in some species.