Spike of spikelet inflorescence is characteristic of

A. Asteraceae

B. Poaceae (Gramineae)

C. Brassicaceae

D. Malvaceae

The spike of spikelet inflorescence is a distinctive feature of the Poaceae family, commonly known as the grass family. So, the correct answer to your question is B. Poaceae (Gramineae).

Understanding Spikelet Inflorescence

To grasp why the spikelet inflorescence is characteristic of Poaceae, let’s break down what a spikelet is. A spikelet is a small unit of the inflorescence in grasses, consisting of one or more florets, which are the individual flowers. These spikelets are arranged along a central stem, known as the rachis, forming a spike or panicle structure.

Characteristics of Poaceae

The Poaceae family includes a wide variety of plants, such as wheat, rice, corn, and many types of grasses. Here are some key features that define this family:

• Floral Structure: The flowers are typically small and lack showy petals, which is a common trait in many grasses.
• Spikelets: As mentioned, the spikelets are the primary floral units, and they can be arranged in different ways, such as in spikes, racemes, or panicles.
• Leaf Structure: Grasses usually have long, narrow leaves with a distinctive sheath that wraps around the stem.

Comparative Analysis with Other Families

Let’s briefly compare Poaceae with the other families listed in your question:

• Asteraceae: This family, known as the daisy family, typically has composite flowers arranged in heads, not spikelets.
• Brassicaceae: Commonly referred to as the mustard family, these plants have four-petaled flowers and do not exhibit spikelet inflorescences.
• Malvaceae: This family includes hibiscus and cotton, characterized by large, showy flowers and not spikelets.

Examples of Spikelet Inflorescence

To illustrate the concept further, consider the following examples of grasses:

• Wheat (Triticum spp.): The spikelets are arranged in a dense spike, making it easy to see how they cluster together.
• Rice (Oryza sativa): Rice plants have a panicle type of inflorescence, where the spikelets are branched out, showcasing the diversity within the family.

Conclusion

In summary, the spikelet inflorescence is a defining characteristic of the Poaceae family, setting it apart from other plant families like Asteraceae, Brassicaceae, and Malvaceae. Understanding these distinctions helps in identifying and classifying various plant species effectively.