Floral Diagram and Formula
The diagram that illustrates the relative position and number of parts present in each whorl in a flower is termed the floral diagram. It provides information about the number of parts of a flower, their arrangement, and the relation they share with one another.
The diagram is mostly drawn on the basis of the position of the mother axis with respect to the flower which is represented as a dot on the top of the floral diagram. The calyx, corolla, androecium, and gynoecium to drawn in successive whorls, as the calyx is placed outermost and the gynoecium is in the center.
It is an expression that summarizes the information given in the floral diagram, in the form of an equation.
On the basis of morphological features, used to describe a flowering plant with its habit, vegetative characteristics -root, stem and leaves, inflorescence, and flower parts, a floral formula and diagram are presented. In a floral formula, the following symbols are used, these are listed in the given picture:
In the floral formula, the cohesion is shown as within parts of whorls, and adhesion is shown as between whorls.
Some important families with descriptions:
The family is earlier known as Papilionoideae, a subfamily of the family Leguminosae it is found all over the world.
Vegetative characters of Fabaceae:
- Trees, shrubs, herbs; roots with root nodules
- Stem: The stem is erect or climber
- Leaves: These are alternate, pinnately compound or simple; leaf base, pulvinate; stipulate; and the venation is reticulate
- The Inflorescence: racemose type
- The Flower: bisexual, zygomorphic flowers
- Calyx: sepals five, gamosepalous; valvate/imbricate aestivation
- Corolla: petals five, polypetalous, papilionaceous, consisting of a posterior standard, two lateral wings, two anterior ones forming a keel (enclosing stamens and pistil), vexillary aestivation
- Androecium: ten, diadelphous, anther dithecous
- Gynoecium: ovary superior, mono-carpellary, unilocular with many ovules, style single
- Fruit: legume;
- seed: one to many, non-endospermic
Floral Diagram and formula:
Economic importance: These are used as ornaments, oils, and edible plants.
- Aparajit, Clitoria ternatea
- Indian coral tree- Erythrina indica
- Sweet pa- Lathyrus odoratus
- Japanese pagoda tree- Spora japonica
- Edible plants:
- Arhar (pigeon pea)- Cajanus cajan
- Chana (Gram, Chickpea)- Cicer arientium
- Soya (soya bean)- Glycine max
- Matar (Garden pea)- Pisum sativum
- French bean- Phaseolus vulgaris etc.
It is a large family, also known as the ‘potato family’. This family is widely distributed in tropics, subtropics, and also in temperate zones.
Vegetative Characters of Solanaceae:
- Plants mostly herbs, shrubs, and rarely small trees
- Stem: The stem is herbaceous rarely woody, aerial; erect, cylindrical, branched, solid or hollow, hairy or glabrous, the underground stem also found in potato (Solanum tuberosum).
- Leaves: Leaves are alternate, simple, rarely pinnately compound, exstipulate; venation -reticulate
- Inflorescence: Solitary, axillary, or cymose as in Solanum
- Flower: bisexual, actinomorphic
- Calyx: sepals five, united, persistent, valvate aestivation
- Corolla: petals five, united; valvate aestivation
- Androecium: stamens five, epipetalous
- Gynoecium: bicarpellary obligately placed, syncarpous; ovary superior, bilocular, the placenta is swollen with many ovules, axile
- Fruits: berry or capsule
- Seeds: many, endospermous
Floral Diagram and Formula:
- Day Jasmine- Castrum diumum
- Night Jasmine – C. nocturnum, Petunia axillaries
- Edible parts:
- tomato- Lycopersicon esculentum
- Potato- S. tuberosum
- Medical use:
- Atropa belladonna, ashwagandha
- Solanum nigrum
- Other uses like – tobacco (Nicotiana tabaccum)- Used for smoking, chewing etc.
These are commonly called the ‘Lily family’ which is a characteristic representative of monocotyledonous plants. It is distributed worldwide.
- Vegetative characters: These are mostly perennial herbs with underground bulbs/corms/ rhizomes
- Leaves: The leaves are mostly basal, alternate, linear, exstipulate with, and parallel venation is found.
- Inflorescence: solitary / cymose; often umbellate clusters
- Flower: bisexual; actinomorphic, trimerous
- Perianth tepal six (3+3), often united into a tube; valvate aestivation
- Androecium: stamen six, 3+3, epitepalous
- Gynoecium: tricarpellary, syncarpous, ovary superior, trilocular with many ovules;
- Placentation: axile placentation, Stigma trifid.
- Fruit: capsule, or rarely as berry
- Seed: endospermous
Floral diagram and formula:
- Glory lily- Gloriosa superba
- Onion- Allium cepa (also used as medicine)
- Garlic- A. sativum
- Satawar- Asparagus recemosus
- Other – Colchicum autumnate– Colchicine (an alkaloid obtained is used to induce polyploidy)
Family Cruciferae: (Brassicaceae)
- Flowers are ebracteate.
- Calyx– Sepals- 4, free
- Corolla- Petals 4, Polypetalous and cruciform.
- Androecium: stamens 6, tetradynamous
- Gynoecium: bicarpellary, syncarpous ovary superior with a false partition (replum), Placentation is parietal
- Fruit– a siliqua or silicula
Floral diagram and formula:
Economic importance of Brassicaceae:
- Basket of Gold- Alyssum saxatile
- Candytuft- Iberis amara
- Wallflower- Cheiranthus cheirl
- Edible plants
- Yellow mustard- Brassica campestris
- Cauliflower- b. oleracea
- Radish- Raphanus sativus, etc.
Poaceae: (grass family)- Graminaceae
Inflorescence: Spike or spikelets or panicle of spikelets.
- Presence of glumes covering spikelets.
- Inner and outer Palea are present, which represents bract and bracteoles respectively.
- Perianth 2-3 reduced, translucent, or succulent scaly structures are called lodicules.
- Androecium: Stamen 3 or some times 6 (3+3)
- Gynoecium: Monocarpellary, unilocular with a single ovule and two feathery stigmas present.
Floral diagram and formula:
Staple food grains:
- Cereals: Wheat- Triticum aestivum, Maize- Zea mays, Rice- Oryza sativa, Oat- Avena sativa, Barley- Hordeum vulgare
- Millets: Jowar- sorghum vulgare, Sugar plant- Sugar cane- Saccharum officinarum, etc.
You can also read:
- The Fruit – Morphology
- The Inflorescence
- Morphology of leaf
- Morphology of stem
- Morphology of roots
- Reproduction in flowering plants
- Morphology of Flower
- You can also read Angiosperms for detailed information about angiosperms.
Thank You 🙂