Grassland Science GRAS 2614

The growth and development of plants over time, including aboveground (leaf, shoot, seed, flower) and underground growth.

The process where dormant seeds develop into seedlings under optimal conditions (water, oxygen, temperature, sunlight).

The critical first step in seed germination, water is absorbed, activating enzymes and triggering metabolic processes.

After water absorption, internal metabolic processes activate, breaking down stored nutrients for the developing embryo.

First visible sign of germination where embryonic root emerges, establishing a root system for water and nutrient absorption.

Protective sheath encasing the developing shoot, protecting it as it emerges from the soil.

The process of converting sunlight into energy, essential for the continued growth of the seedling.

The region of active growth at the base of the plant (crown), where cell division, elongation, and differentiation occur.

Structures from which different tissues of the grass shoot develop – young leaves originate as small swellings.

Consists of the leaf sheath (attaches blade to shoot) and leaf blade (lamina), joined by connective tissue called the collar.

Occurs when top meristem changes from vegetative to reproductive, inhibiting secondary shoot formation and forming flower primordia.

Transition from vegetative to reproductive growth is regulated by light, temperature, and cold treatment.

Low-temperature stimulation under natural conditions, required for flower formation in temperate zones.

Structure where apical meristem shifts from producing leaves/stems to forming reproductive parts (spikelets and florets).

Basic reproductive unit in grasses, containing one or more flowers (florets) protected by bracts.

The outer bracts at the base of spikelet

The outer bract that surrounds and protects the florets

The inner bract that surrounds the florets

Male reproductive organs (stamens) that produce pollen.

Female reproductive organ (pistil) which contains the ovary, style, and stigma.

Flowering involves development/maturation of stamens and pistils; grasses are monoecious (both sexes on one plant) or dioecious.

Anthers mature and release pollen, transferred by wind in most grasses (anemophilous = wind-pollinated).

Process where pollen travels down the stigma to the egg cell, forming a zygote and leading to seed development.

The outer layers of the ovule harden and become the seed coat, which protects the seed

The starchy endosperm stores nutrients that will support the embryo during germination.

The embryo (young plant) within the seed starts to develop its root, shoot, and leaves.

Two types: primary (temporary, from seed) and permanent (secondary). Distribution in soil defines grass classes.

Especially annuals, and also Eragrostis species, Cymbopogon plurinodis and sometimes Themeda triandra.

Digitaria tricholaenoides and Elionurus muticus..

Cynodon dactylon, Themeda triandra,Tetrachne dregei and Brachiaria serrata.

A family of flowering plants known as grasses; it's the fifth-largest angiosperm family, containing approximately 10,000 species across 900 genera.

Uncultivated land with indigenous vegetation that can be grazed by animals.

A plant with one cotyledon, fibrous roots, flower petals in multiples of three, narrow parallel leaf veins, and scattered vascular bundles.

Warm season grasses thrive with better drought tolerance, adapted to hot, dry climates, growing actively in warm months and becoming dormant in cooler months.

Cool season grasses thrive with better cold tolerance, flourishing in regions with cold winters, showing peak growth in cooler seasons and slowing in warm months.

The stem of a grass plant is typically hollow, with solid nodes at regular intervals.

The leaf part is long, narrow and originates at the nodes.

A sheath is the lower part of a grass leaf that encloses the stem.

The collar and ligule are located at the junction of the leaf blade and sheath.

A type of root system characterized by a dense network of thin roots.

Horizontal stems that grow above ground, producing new plants at the nodes.

Horizontal underground stems that produce new plants from nodes.

Contains spikelets and seeds and fruits called caryopsis.

A dry, one-seeded fruit in which the seed coat is fused to the ovary wall (common in grains).

Includes stems, leaves (sheath, collar, and blade).

Includes inflorescence comprised of spikelets.

Plant family that has 3-ranked leaves, closed sheaths, stems not jointed or hollow, and less conspicuous flowers.