Biology · Morphology of Flowering Plants · NEET
The pea flower is zygomorphic (bilaterally symmetrical). It can be cut into two equal halves in only one vertical plane. NCERT lists pea, gulmohur, bean and Cassia as zygomorphic examples. This is why NEET keeps pairing Pisum with 'zygomorphic' and keeping Datura or mustard as the actinomorphic trap.
Diadelphous means the 10 stamens are joined into two bundles. In pea, 9 stamens fuse into one bundle and 1 stamen stays free, written as (9)+1. Compare: monadelphous = one bundle (China rose), polyadelphous = many bundles (Citrus). Diadelphous is the stamen feature unique to Fabaceae among the NEET families.
These are the 5 petals of the vexillary corolla. The single largest posterior petal is the standard (also called vexillum). The two lateral petals are the wings (alae). The two fused anterior petals form the keel (carina). Order by position: posterior = standard, lateral = wings, anterior = keel.
Fabaceae has a superior, monocarpellary (single carpel) ovary with marginal placentation. The placenta forms a ridge along the ventral suture and ovules sit in two rows. The fruit that develops is a legume (pod). NEET often matches 'Pea' with 'marginal placentation'.
Yes. Vexillary aestivation and papilionaceous corolla describe the same pea-type petal arrangement: the standard overlaps the two wings, which in turn overlap the two keel petals. NEET uses both words for the same thing, so treat them as synonyms.
Fabaceae (Leguminosae) is the whole legume family. Papilionoideae is the subfamily with the butterfly-shaped (papilionaceous) flower that NCERT describes for pea and bean. For NEET, the floral features you study (vexillary corolla, diadelphous stamens) are specifically the Papilionoideae characters, so the two names are used interchangeably in this chapter.
In a pea flower, five petals are arranged in a specialized manner with one posterior, two lateral and two anterior. These are named as ________, ________ and ________ respectively.
Which one of the following plants shows vexillary aestivation and diadelphous stamens?
Family Fabaceae differs from Solanaceae and Liliaceae. With respect to the stamens, pick out the characteristic specific to family Fabaceae but not found in Solanaceae or Liliaceae.
Try the real previous-year questions from this chapter — each with the answer and a full solution.
The floral formula is: % (zygomorphic), bisexual, K(5) fused sepals, C1+2+(2) vexillary corolla, A(9)+1 diadelphous stamens, G1 superior monocarpellary ovary. In symbols: % ⚥ K(5) C1+2+(2) A(9)+1 G1.
Fabaceae forms a legume (also called a pod). It develops from the single superior carpel and splits along both sutures when ripe. Examples: pea pod, bean pod, gram.
Pisum sativum (pea), Cicer arietinum (gram), Arachis hypogaea (groundnut), Glycine max (soybean), Trifolium (clover), Cassia and Sesbania. Many are pulses rich in protein and fix nitrogen through root nodules.
The corolla shows vexillary (papilionaceous) aestivation: the largest posterior petal (standard) overlaps the two lateral wings, which overlap the two anterior keel petals. This descending overlap is the vexillary pattern.
Fabaceae gives pulses (protein food), edible oil (groundnut, soybean), fodder (Sesbania, Trifolium), dyes (indigo), fibres, ornamentals (lupin) and medicine. Their root nodules fix atmospheric nitrogen, improving soil fertility.
