Q.Distinguish between racemose and cymose inflorescence.

The pattern in which flowers are arranged on the peduncle (floral axis) is called inflorescence.

When the shoot apex converts to a reproductive (floral) meristem, it may bear a single flower or, more commonly, a cluster of flowers arranged along the elongated floral axis in a characteristic pattern; this pattern is termed the inflorescence. Broadly, inflorescences are classed as racemose (the main axis continues to grow and produce flowers laterally, so the youngest flowers are near the apex, e.g. raceme, spike, panicle) or cymose (the main axis terminates in a flower, so the oldest flower is at the apex/centre, e.g. cyme). The type of inflorescence is an important taxonomic character used to distinguish plant families.

The main axis of an inflorescence (the stalk of the whole flower cluster) is called the peduncle.

In flowering-plant morphology, when the shoot apex transforms into a reproductive (floral) apex, it either produces a single flower or a group/cluster of flowers arranged on the main axis, this arrangement is called an inflorescence.

• The main stalk that bears the whole cluster of flowers is the peduncle.
• The individual stalk of each flower borne on that axis is the pedicel.
• Rachis refers to the elongated central axis on which sessile flowers/leaflets are directly arranged (e.g. the axis of a compound leaf), and is sometimes used loosely for the floral axis bearing sessile flowers, but the standard term asked for the inflorescence axis itself is peduncle.
• Petiole is the stalk of a leaf, unrelated to flowers.

So the axis of the inflorescence as a whole is termed the peduncle.

Thyrsus combines a racemose main axis with cymosely-branched lateral branches, which is why it is classified as a mixed (compound) type of inflorescence rather than purely racemose or purely cymose.

Inflorescences are broadly grouped as:

• Racemose — the main axis continues to grow indefinitely, producing flowers laterally in acropetal succession (younger flowers near the tip).
• Cymose — the main axis terminates in a flower early, so growth continues through lateral (definite) branches, in a basipetal-appearing succession.
• Mixed (compound) inflorescences — combine both patterns, typically a racemose main axis bearing cymosely-arranged lateral branches (or vice versa), and special inflorescences with unique structural modifications (e.g. cyathium, hypanthodium, verticillaster).

Thyrsus is a compact, often pyramidal or conical panicle in which the main axis is racemose (indeterminate) but each of its lateral branches ends in a cyme. A familiar example is the inflorescence of grapevine (Vitis vinifera) and some members of the mint family. Because it structurally mixes both the racemose and cymose growth patterns within one inflorescence, thyrsus is placed under mixed (compound) inflorescences, not treated as a purely cymose, purely racemose, or 'special' type.

Ficus (Peepal) bears a hypanthodium inflorescence → (d).

• A hypanthodium is a cup/flask-shaped, hollow receptacle enclosing tiny male, female and neuter flowers, with a small apical pore (ostiole).

• It is characteristic of the genus Ficus — Peepal, banyan and fig.

• Spadix, spike and cyathium are different inflorescence types.

A cyathium is a cup-like involucre of fused bracts enclosing one central female flower surrounded by many reduced male flowers — a hallmark of the genus Euphorbia.

In a cyathium, a cup-shaped structure formed by fused bracts (the involucre) bears a single, stalked female flower in its centre, surrounded by numerous highly reduced male flowers (each reduced to essentially a single stamen). This condensed, specialised inflorescence is a defining feature of the family Euphorbiaceae, particularly the genus Euphorbia (e.g., Euphorbia pulcherrima — poinsettia, Euphorbia hirta, Euphorbia milii).

Checking the other options: Mango bears a panicle inflorescence, Bougainvillea (the option likely intended by "Darcitonia") bears a cyme, and Anjir/fig (Ficus) bears a hypanthodium. None of these is a cyathium.

A spike is a racemose inflorescence with sessile flowers on an unbranched, elongated axis.

Inflorescences are broadly classed as RACEMOSE (the main axis keeps growing and does not end in a flower, so flowers open acropetally - oldest at the base, youngest at the apex) or CYMOSE (the main axis terminates in a flower, so growth stops and flowers open basipetally - youngest at the base). A SPIKE is a classic racemose type: like a raceme, but the flowers are sessile instead of pedicellate (e.g. Achyranthes, Amaranthus). "Special" and "mixed" inflorescences are separate descriptive categories (e.g. spadix, cyathium, verticillaster) and not the general class a spike belongs to.

In a cyathium, the male flowers (each reduced to one stamen) and the single central female flower (a single pistil) are both unisexual, unlike the bisexual flowers of a verticillaster, cyme, or thyrsus.

A cyathium is a specialised inflorescence in which a cup-like involucre of fused bracts encloses many male flowers, each reduced to just a single stamen jointed to a pedicel (mimicking a filament), arranged around one central female flower reduced to a single stalked pistil. Because each individual flower has only male or only female parts, both flower types in a cyathium are strictly unisexual.

A verticillaster (whorled cymes in the leaf axils, typical of the mint family), a simple cyme, and a thyrsus (a panicle-like arrangement with a racemose main axis and cymose lateral branches) typically bear ordinary bisexual flowers, not unisexual ones.