Botany and Plant Science

The peduncle is the main axis or stalk that bears the entire inflorescence (cluster of flowers). A pedicel is the stalk of an individual flower within an inflorescence, while stipules are leaf-like structures at the base of petioles, and bracts are modified leaves associated with flowers.

Canna flowers are asymmetrical (zygomorphic) with unequal petal/sepals and irregular bilateral symmetry. Crotalaria, Hibiscus, and Tridax all have regular (actinomorphic) flowers that can be divided into equal halves through multiple planes.

Underground stems like rhizomes, tubers, and bulbs have scale leaves - small, membranous, protective structures that don't photosynthesize much. Aerial stems have fully expanded green leaves, and sub-aerial stems have reduced or normal leaves depending on type.

Bracts are specialized or modified leaves that bear flowers in their axils (the angle between the bract and stem). They're not regular sepals or petals, though they may resemble them. 'Tepals' refer to undifferentiated perianth parts, not related to bracts.

Polyphyllous means floral parts (sepals, petals, stamens, carpels) are free and separate from each other. Gamophyllous means parts are fused. Polygamous describes plants with both bisexual and unisexual flowers. Syncarpous refers to fused carpels in gynoecium.

Acropetal succession means flowers open from base (older) to apex (younger). Basipetal is opposite (apex to base). Centrifugal refers to development from center outward, not opening sequence. 'Either' creates ambiguity about basipetal vs centrifugal.

Runners, stolons, offsets, and suckers are all sub-aerial stem modifications that grow horizontally at or just above ground level for vegetative propagation. Aerial stems grow upright; climbers and twiners are growth habits not stem types.

Anisomerous flowers have unequal numbers of parts in different floral whorls (e.g., 5 sepals, 4 petals). Isomerous flowers have equal numbers (e.g., 5 sepals, 5 petals). Pentamerous (5 parts) and tetramerous (4 parts) are specific isomerous types.

Zygomorphic flowers have bilateral symmetry - only one plane can divide them into mirror halves (orchids, peas). Actinomorphic flowers have radial symmetry with multiple planes. Polygamous means having both bisexual and unisexual flowers. Perianth refers to calyx+corolla.

A compound leaf's blade is divided into leaflets (pinnae is the technical term). 'Leaf-lets' is the common descriptive spelling. Rachis is the central axis of compound leaf. Option D 'either (1) or (2)' correctly allows both common and technical terms.

Suckers are lateral branches that develop from axillary buds on the underground part of the stem. They grow upward from the base of the plant and can form new clonal plants. Climbers and twiners are climbing strategies, while herbs refer to non-woody plants - none specifically describe underground lateral branches.

In compound leaves, the term 'pinna' (plural: pinnae) refers to the individual leaflets that make up the compound leaf. The main leaf is the entire compound structure, the rachis is the central axis, and feather is the literal meaning of the Latin word pinna, not the anatomical structure.

The word 'pinna' comes from Latin, meaning 'feather' or 'wing'. In compound leaves, pinnae (leaflet divisions) are arranged like the barbs of a feather. This etymology reflects the feather-like appearance of pinnately compound leaves, where leaflets are arranged along both sides of a central rachis.

Dichlamydeous flowers possess both accessory whorls: the calyx (outer whorl of sepals) and the corolla (inner whorl of petals). The prefix 'di-' means two, referring to these two accessory whorls. Monochlamydeous flowers have only one, and achlamydeous flowers lack both. Diadelphous refers to stamen fusion, not whorls.

A thyrsus is an inflorescence type where simple cymes (compound dichasial cymes) are arranged in a racemose manner along the main axis. Verticillaster has clusters in verticils, monochasial has single lateral branches, and hypanthodium is a flask-shaped receptacle found in fig.