Weed Biology and Identification-206 Target students: M.Sc. Students in Weed Science Lecture: Dr. Majid AghaAlikhani (Ph.D.) Academic position : Associate Prof. of Tarbiat Modares University 1

Classification of Plants

Plant Kingdom Flowering Plants Non-flowering Plants

. 3 groups FernsMossesGymnosperms Non - flowering Plants Do NOT produce flowers

A plant can be divided into 3 parts

Land Plants - Embryophytes Liverworts, Hornworts, Mosses

Examples of Mosses

spores Spore-producing capsule

. No true roots, No vascular tissues (no transport) Characteristics of Mosses. Simple stems & leaves. Have rhizoids for anchorage. Spores from capsules (wind-dispersal). Damp terrestrial land. Simplest plants

Vascular Plants - Tracheophytes Lycophytes (Lycopods) Isoetes orcuttii Selaginella apoda Selaginella bigelovii

Vascular Plants Equisetophytes (Equisetales): Equisetum Equisetum arvense Common Horsetail Equisetum spp. Scouring-Rush

Vascular Plants Ophioglossoid Ferns (Ophioglossales) Ophioglossum californicum Calif. Adder’s Tongue

Vascular Plants - Tracheophytes Psilotophytes (incl. Psilotum, Tmesipteris)

Vascular Plants - Tracheophytes Marratiophytes

Vascular Plants Leptosporangiate Ferns (Polypodiales) Polypodium californicum California Polypody Dryopteris arguta Coastal Wood Fern

underground stem root A leaf (finely divided into small parts)

. roots, feathery leaves & underground stems Characteristics of Ferns vascular tissues. have vascular tissues (transport & support) Dampshady. Damp & shady places Spore-producing organ. Spore-producing organ on the underside of leaves (reproduction)

Seed Plants: Gymnosperms Cycads Ginkgo Cycas circinalisGinkgo biloba

Abies concolor White Fir Pinus torreyana Torrey Pine Cupressus forbesii Tecate Cypress Conifers

needle-shaped leaves

Male cones (in clusters) Female cones (scattered)

. roots, woody stems Characteristics of Gymnosperms. needle-shaped leaves. tall evergreen trees. cones with reproductive structures. dry places. vascular tissues (transport). naked seeds in female cones

Ephedra spp. Mormon Tea Gnetales Welwitschia mirabilis

Seed Plants: Angiosperms - Flowering Plants

. 2 groups MonocotyledonsDicotyledons Flowering Plants. roots, stems, leaves. vascular tissues (transport). flowers, fruits (contain seeds)

parallel venation Monocots 1 cotyledon floral parts in 3’s (often) radicle epicotyl hypocotyl 1 cotyledon embryo coleorhiza coleoptile radicle epicotyl 1 cotyledon MONOCOTS

Monocotyledons Parallel veins

. one seed-leaf Characteristics of Monocotyledons. leaves have parallel veins. herbaceous plants. e.g. grass, maize

Dicotyledons Veins in network

net venation Eudicots 2 cotyledons floral parts in 4’s or 5’s (often) embryo seed coat radicle epicotyl hypocotyl 2 cotyledons endosperm NON-MONOCOT {

. two seed-leaves Characteristics of Dicotyledons. leaves have veins in network. e.g. trees, sunflower, rose

Plant Classification Non-flowering Plants Flowering Spore- bearing Naked seeds No roots with roots MossesFerns Gymnosperms 1 seed- leaf 2 seed- leaves MonocotsDicots