Poaceae and Cyperaceae Dr. Prachi P. Kshirsagar Agharkar Research Institute, Pune

Introduction to Grasses (Poaceae) Also known as Graminae (Grass family, True grass) Largest family of economic and ecological importance In India 268 genera and 1200 species of grasses Grasslands occupy 25% of earths vegetation Distributed in all continents and in all climatic zone (Arctic, Antartic and Ice covered zone) Grow in marshes, deserts, prairies, woodlands, on sands, rocks, in all soil types and from sea level to highest elevation Most successful life form on earth Important component in food chain Annuals or perennials Few centimeter herbs to 25 feet bamboos Tolerable to long period of drought

Introduction to Grasses (Poaceae) Roots always fibrous (arises from lower node), stilt roots present in some grasses e.g. zea mays Rhizome – underground stem Stolon – creeping stolon Stem (Culm) – Aerial stem are hollow or flattend with hollow internode and solid node Nodes hairy or glabrous

Leaves composed of three part Leaves born in two rows alternately along the culm at the nodes. Leaves composed of three part a. Leaf Sheath – originates from node of the stem and surrounds the culm b. Leaf Blade – linear lanceolate with parallel venation c. Ligule – thin membranous or fringe of hairs at the junction of sheath and blade

open sheath ligule

GRASS FLOWER The grass flower is very small, inconspicuous and reduced. It consists of gynoecium, androecium and lodicules. The flower has two tiny basal scales called lodicules (reduced perianth). Glumes, rachilla and one to many florets together form a spikelet Rachilla – central axis on which florets borne Glumes – Pair of bract present at the base of spikelet Spikelet Florets

GRASS FLOWER Floret In between Lemma and Palae, a single flower is located Spikelet These tiny flowers are protected by two bracts, lower is the lemma and upper is the palea. Awns are present on Lemma The flower with its lemma and palea is called a floret. The floret is always 1-flowered with one lemma and one palea (sometimes palea may be absent).

GRASS FLOWER Floret Flower Spikelet

GRASS FLOWER Floret Flower Spikelet 1st glume Pedicel

Flowers of Grasses Glume

Spikelet - Diagrammatic Flower Spikelet

Fruit of Grass Commonly known as ‘Grain’ Caryopsis - dry, indehiscent, 1 seeded fruit Commonly known as ‘Grain’

Importance of Grasses 1. Agricultural grains (most important food in world): barley (Hordeum) corn (Zea) oats (Avena) rice (Oryza) rye (Secale) wheat (Triticum); 2. Forage and grazing plants; 3. Important components of many ecosystems, such as grasslands and savannahs. 4. Grasses are good soil binders 5. Some grasses have medicinal value 6. Some grasses yield essential oil e.g. Tikhadi 7. Also useful in paper making and in some miscellaneous uses e.g. matting, making ropes, furniture, stuffing for pillow, brooms and musical instrument. 8. Grasses constitute major ground cover and make significant contribution to biomass production.

Introduction to Sedges (Cyperacea) Grass like herbaceous plants mostly found in wet regions. Annual, or biennial, or perennial Members are distributed throughout all the continents except Antarctica. Diversity is far greater in tropical regions occurs in all habitats except extreme deserts and marine and deep-water ecosystems Sedges love sunny, moist to wet habitats such as fresh and salt marshes, pond and lakeshores, meadows, bogs, fens, wet prairies and savannas, and moist to wet tundra Few sedges are crop plants e.g. Chinese water chestnut (Eleocharis dulcis), yellow nut sedge (Cyperus esculentus) in Africa (Tuber edible)

Introduction to Sedges (Cyperacea) Used in weaving mats, baskets, screens, and sandals because of their strong, fibrous stems and leaves (Cyperus tagestes grown in India) People on Titicaca Lake, in the Andes, use tatora (Schoenoplectus tatora) to construct small boats called balsas for traversing the lake Cyperus papyrus was used in ancient Egypt for making paper and for constructing boats The ecological importance of sedges is extraordinary. Plays important role in succession Important component in wetland produces bulk food for aquatic animals (Tubers and fruits) Large stands of sedges are also critical as cover for many wetland animals.

Cyperaceae - Morphology Sedges range in size from less than 1 centimetre (e.g. Eleocharis ) to a height of 5 metres in papyrus. Some species of Scleria, are scrambling vines up to 10 metres long. A few species of Gahnia have woody stems, and West African Microdracoides squamosus is a woody shrub up to 1.5 metres tall. Stem with a basal aggregation of leaves (usually), or with neither basal nor terminal aggregations of leaves. Roots rhizomatous or tuberous. Leaves alternate; spiral (rarely), or distichous (often), or tristichous (usually); flat, or folded (and occasionally plicate), or rolled. Leaf sheaths closed. Leaves simple, ligulate (commonly), or eligulate. Lamina entire parallel-veined

Cyperaceae – whole plant

Cyperaceae - Flower Flowers are arranged in spikelets somewhat as in grasses, and these again in larger spike-like or panicled inflorescences Flowers are often unisexual, are wind-pollinated Flowers bracteate, or ebracteate; bracteolate (each borne in the axil of a ‘glume’); usually small, or minute. Perianth of ‘tepals’(represented by bristles or hairs), or absent; when present, often 6, free Androecium 1–3, or 4–6(–22). Androecial members free of the perianth; free of one another (usually) Gynoecium 2 carpelled, or 3 – 4 carpelled, syncarpous; Styles 2–3; free to partially joined. Stigmas 1–2, or 3–15

Cyperaceae - Flower

Cyperaceae – schematic representation of spikelet

First scale on a lateral spikelet is prophyll (Bracteole) Spikelet consist of a spikelet axis (rachila) and few to numerous spirally or distichously arranged glumes, each subtending one unisexual or bisexual flower First scale on a lateral spikelet is prophyll (Bracteole) Internodes between prophyll and second glume is epipodium Proximal glume Prophyll

Cyperaceae - Fruit Fruit non-fleshy; indehiscent achene-like, or a drupe (very rarely), 1 seeded, endospermic.

Difference Between Poaceae and Cyperaceae Family Stem Leaves Flower Fruit Poaceae Rounded, hollow at internodes Ligulate, sheaths open, 2 ranked Modified into glumes, lemmas and paleas Caryopsis Cyperaceae 3 – sided, solid Sheath closed, 3 ranked Scales Achene

Difference between stem Poaceae Poaceae Cyperaceae Cyperaceae

CYPERACEAE Cyperus alternifolius Cyperus polystichus Carex amphibola Cyperus rotundus

Sedges have edges Rushes are round Grasses have nodes from the top to the ground

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