11 Biology

Plant Morphology

DESCRIPTION OF SOME IMPORTANT FAMILIES

Fabaceae

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

floral diagram of fabaceae

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; 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 of fabaceae

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.

floral diagram of solanaceae

Vegetative Characters: Plants mostly, herbs, shrubs and 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, syncarpous; ovary superior, bilocular, placenta swollen with many ovules

Fruits: berry or capsule
Seeds: many, endospermous

Floral Formula

floral formula of solanaceae

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 worldwide.

floral diagram of liliaceae

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: petal six (3+3), often united into tube; valvate aestivation
Androcium: stamen six, (3+3)
Gynoecium: tricarpellary, syncarpous, ovary superior, trilocular with many ovules; axile placentation

Fruit: capsule, rarely berry
Seed: endospermous

floral formula of liliaceae

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