🌼 🍃 Intermediate Practical Manual - Inflorescences

on

🌼 Special Types of  Inflorescences

🔹 Simple umbel: Onion (Allium cepa)

The given specimen shows the following characters:

  1. There is a cluster of bracteate and pedicellate flowers at the apex of an unbranched peduncle.

  2. Bracts of all the flowers are arranged in a whorl at the base of the inflorescence forming a membranous structure called involucre.

  3. Flowers are centripetally arranged.

👉 By the above characters, the specimen is identified as a simple umbel type of racemose inflorescence.

📷 Diagram shows Onion umbel with involucre of bracts.

🔹 Simple spadix: Colocasia

The given specimen shows the following features:

  1. The peduncle is fleshy and unbranched.

  2. Three types of flowers (male, neuter, and female) are present on the peduncle. They are arranged in acropetal manner.

  3. Male flowers are placed at the top of the peduncle.

  4. Female flowers are present at the bottom of the peduncle.

  5. Neutral flowers occur in between male and female flowers.

  6. Entire inflorescence is covered by a leathery bract called spathe.

  7. The terminal part of the peduncle is flowerless, called appendix.

👉 By the above characters, the specimen is identified as a simple spadix type of racemose inflorescence.

📷 Diagram shows Colocasia spadix with spathe, male, neuter, and female flowers.

🔹 Verticillaster (Leucas)

Characters:

  1. Appears as a false whorl around the node.

  2. Originates in the axils of two opposite leaves.

  3. Flowers are first in a dichasial cyme, later in a monochasial scorpioid cyme.

  4. Flowers open in centrifugal manner.

👉 Identified as Verticillaster (special type of inflorescence).

📷 Diagram: Leucas inflorescence with bracts.

🔹 Cyathium (Euphorbia)

Characters:

  1. Inflorescence resembles a single flower.

  2. Involucre of bracts forms a cup-like structure.

  3. Nectar glands present outside the cup.

  4. One long-stalked female flower at the centre.

  5. Female flower has tricarpellary, syncarpous, trilocular ovary.

  6. Each male flower = single stamen.

  7. Male flowers arranged in scorpioid manner around female flower.

  8. Both male & female flowers are achlamydeous (no perianth).

👉 Identified as Cyathium (special type of inflorescence).

📷 Diagram: Euphorbia cyathium showing male & female flowers.

🔹 Hypanthodium (Ficus)

Characters:

  1. It is a fruit-like inflorescence.

  2. Structure is cup-shaped by peduncle.

  3. Cup has hollow cavity with apical opening.

  4. Flowers borne on inner wall of cavity.

  5. Three types of flowers: male, female, sterile female (gall).

  6. Male flowers near opening, female flowers at base, gall flowers in between.

  7. Opening of flowers is irregular.

👉 Identified as Hypanthodium (special type of inflorescence).

📷 Diagram: Ficus hypanthodium with female, gall & male flowers.

👉🔬 Intermediate Practical Book 


Comments

Post a Comment