BOT 2150 CPlant classification Lecture 1, May 11
What makes a plant?• Photosynthetic and contain chlorophyll a & b• Multicellular• Alternates between two generations• Produces embryos• Has cell walls made of cellulose• Mushrooms are not plants!
Plant kingdomNon-vascular Vascular (Tracheophyta) Plants without seeds Mosses Liverworts (Seedless vascular Plants with seeds(very moist areas) plants) (seeded vascular plants) Horsetails Ferns Gymnosperms: Angiosperms: Fronds & cones flowers & fruits spores Wetter areas
Gymnospermspage 2 Conifers Often trees with needle-like or scale-like leaves, male and female cones; female cones produce seeds (includes Podocarps) Cycads Large, pinnately compound leaves, male and female cones, cones large and colorful; female cones produce seeds Others: Ginko biloba Gnetales
angiosperms Monocots – one seed cotyledon, parallel leaf veins, flowers with multiples of 3 (3, 6, 9), stems lack secondary growth, most are herbaceous, fibrous root systems Eudicots – (dicots), 2 seed cotyledons, veins are usually netted, flowers are in multiples of 4 or 5, stems may have secondary growth, many are herbaceous, many are woody, tap root systems (fleshy included in this category) Others: Basal angiosperms Includes groups that are not monocots or eudicots Ex: water lily
Plant Monocot “Dicot”characteristicPlant 2,700/ 58,000 9,900/175,700genera/species(approx.)Cotyledons 1, usually develop 2, usually develop underground or above the ground inside the fruitMature root adventitious, often Mostly taprootsystem above ground, often system, prop roots occasionally adventitiousLeaf venation Usually parallel Usually netted
Stem Scattered; Arranged in a ring appearing around the stem; pith random distinctCambium Usually absent - Usually present – “true” no true secondary growth secondary growthHabit herbaceous Woody or herbaceousFloral parts Typically in Typically in multiples of multiples of 3 4 or 5Propagation Underground stem or seed Propagate from stem or leaf cuttings (success depends on the species and various techniques); seed, some tubers or underground stems will grow.
Scientific namesIndividual: Theobroma cacao Quercus virginiana Cacao Live OakClassificationKingdom Plantae PlantaeDivision (Phylum) Magnoliophyta MagnoliophytaClass Angiospermae (flowering Angiospermae (flowering plants) plants)Order Malvales FagalesFamily Malavaceae (hibiscus family) FagaceaeGenus (pl. genera) Theobroma QuercusSpecies Theobroma cacao Quercus virginiana Just remember: King David Came Over For Good Soup
Other termsOther terms HybridsSubspecies: ssp. Species hybrid: Cattleya skinneri X guatemalensisVariety: var.Cultivar (cultivated variety): Variety hybrid: Maypan (Malay dwarfcv “Malay dwarf” or “big boy” X Panama tall)
activity• Plants in the room – identify to basic group• Moss (non-vascular), fern, gymnosperm, angiosperm• Nursery tour
Vegetative characteristics-stems• Support structure of the plant• Hold leaves• Figure 22 page 9• Read specialized stem structure pages 9-15
activity• Two example stems• For each stem determine: – 1. leaf type – 2. leaf shape – 3. leaf arrangement – 4. leaf margin
Reproductive organs• Flowers & fruit – only in angiosperms (pg 28-32) Collectively Collectively = calyx = corolla pedicel
Flower terminology cont.• Perfect – contains all parts, both male (stamens) and female (pistil)• Imperfect – does not contain all parts, only male or female flower• Naked flower – usually wind pollinated, no petals or sepals, often imperfect
Reproductive organs - inflorescence• Flowers are found on a stem (peduncle)• The flowering stem with flowers is called an inflorescence• Page 23-27