Question

Spike of spikelet inflorescence is a characteristic of
A) Asteraceae
B) Poaceae (gramineae)
C) Brassicaceae
D) Malvaceae

Answer 1

Hint: A spikelet comprises 2 bracts, or glumes, at the base, accompanied by one or more florets. A floret comprises 2 bracts of the flower, the lemma, one external, the lemma, and one internal, the palea.

Complete Answer:
In botany, a spikelet represents the usual arrangement of grass blossoms. There are one or two florets on each spikelet. The spikelets are further separated into spikes or panicles. The rachilla is considered the part of the spikelet that bears the florets.

Now, let us find the solution from the options-
- Many Asteraceae members are perennial herbs or annual, but shrubs, trees or vines, are also a large number. With species ranging from Polar Regions to tropical areas, the family seems to have a cosmopolitan distribution, colonizing a wide range of environments. In the arid and semiarid areas of subtropical and low temperate latitudes, the highest percentage of the species exists. In certain parts of the world, the Asteraceae may constitute as much as 10 percent of the autochthonous flora.

- Poaceae flowers are distinctively arranged in spikelets, with one or two florets each. The spikelets are further separated into spikes or panicles. The rachilla is considered the section of the spikelet containing the florets. The flowers are typically hermaphroditic, with maize being a notable exception, and wind- pollinated or anemophilous in particular, while insects also play a role. Two scales of the perianth are reduced, called lodicules.

- Brassicaceae is a medium-sized and economically valuable flowering plant genus, generally referred to as the genus of mustards, crucifers, or cabbages. Most of them are herbaceous species, some of them shrubs, with simple, but often deeply incised, alternately set leaves lacking stipules or in leaf rosettes, with terminal inflorescences lacking bracts, comprising flowers with four sepals, four free separate petals, two small and four longer valid stamens, and a thin wall separating fruit of seeds in rows.

- In specific or unspecified axillary inflorescences, the flowers are usually borne, sometimes reduced to a single bud, but can also be cauliflorous, opposite or terminal. In the configuration of a bicolor unit, they also bear supernumerary bracts. They may be bisexual or unisexual and are usually actinomorphic and shape an epicalyxx, often paired with noticeable bracts it.

Thus, the correct answer is option (B) Poaceae (gramineae).

Note: The palea is the topmost of the dual chaff-like bracts which encircle the grass floret. At the tip, it is always cleft, meaning that it can be a double arrangement formed from the fusion of two different organs.