FLOWER FAMILIES

NCERT 11TH STANDARD BIOLOGY – FLOWER FAMILIES , FLORAL FORMULAS

Fabaceae

This family was earlier called Papilionoideae, a subfamily of family Leguminosae. It is distributed all over the world.

Vegetative Characters

Trees, shrubs, herbs; root with root nodules

Stem: erect or climber

Leaves: alternate, pinnately compound or simple; leaf base, pulvinate; stipulate; venation reticulate.

Floral characters

Inflorescence: racemose

Flower: bisexual, zygomorphic

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 Formula: % K(5) C1+2+(2) A(9)+1G1

Economic importance

Many plants belonging to the family are sources of pulses (gram, arhar,sem, moong, soyabean; edible oil (soyabean, groundnut); dye (Indigofera);fibres (sunhemp); fodder (Sesbania, Trifolium), ornamentals (lupin, sweet pea); medicine (muliathi).

Solanaceae

It is a large family, commonly called as the ‘potato family’. It is widely distributed in tropics, subtropics and even temperate zones.

Vegetative Characters

Plants mostly herbs, shrubs and rarely small trees

Stem: herbaceous rarely woody, aerial; erect, cylindrical, branched, solid or hollow, hairy or glabrous, underground stem in potato (Solanum tuberosum)

Leaves: alternate, simple, rarely pinnately compound, exstipulate; venation reticulate

Floral Characters

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, placenta swollen with many ovules, axile

Fruits: berry or capsule

Seeds: many, endospermous

Floral Formula:    ⨁K(5)C(5) ͡ A5G(2)

Economic Importance

Many plants belonging to this family are source of food (tomato, brinjal, potato), spice (chilli); medicine (belladonna, ashwagandha); fumigatory (tobacco); ornamentals (petunia).

Liliaceae

Commonly called the ‘Lily family’ is a characteristic representative of monocotyledonous plants. It is distributed world wide.

Vegetative characters:

Perennial herbs with underground bulbs/corms/rhizomes

Leaves mostly basal, alternate, linear, exstipulate with parallel venation

Floral characters

Inflorescence: solitary / cymose; often umbellate clusters

Flower: bisexual; actinomorphic Perianth tepal six (3+3), often united into tube; valvate aestivation

Androecium: stamen six, 3+3, epitepalous

Gynoecium: tricarpellary, syncarpous, ovary superior, trilocular with many ovules; axile placentation

Fruit: capsule, rarely berry

Seed: endospermous

Floral Formula: Br ⨁P(3+3)  ͡  A(3+3) G(3)

Economic Importance

Many plants belonging to this family are good ornamentals (tulip, Gloriosa), source of medicine (Aloe), vegetables (Asparagus), and colchicine (Colchicum autumnale).

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