Flowers PDF

BIOL 1100: Plant Organ FLOWERS Prepared by: Antoinette P. Dela Cruz Flowers  Reproductive organs  Sexual reproduction External Features of a Flower A. Non-essential Parts B. Essential Parts A. Non-essential ❑ Peduncle – flower stalk ❑ Receptacle – bears...

BIOL 1100: Plant Organ FLOWERS Prepared by: Antoinette P. Dela Cruz Flowers  Reproductive organs  Sexual reproduction External Features of a Flower A. Non-essential Parts B. Essential Parts A. Non-essential ❑ Peduncle – flower stalk ❑ Receptacle – bears some or all of the flower parts ❑ Sepals (calyx) – cover and protect the flower parts (bud) ❑ Petals (corolla) – attract insects ❑ Perianth – combination of corolla and calyx B. Essential ❑ Parts that are considered essential are involved in sexual reproduction. ❑ Stamens (male) – androecium Filament – stalk of stamen Anther – a sac-like structure that contains pollen grains 1 cell 2 sperm cells 1 cell pollen tube B. Essential ❑ Pistil/Carpel (female) - gynoecium Carpels – the basic units of the gynoecium and may be free (distinct) or fused (connate) Pistil – single carpel or fused carpels Stigma – where the pollen lands B. Essential Style - stalk of carpel Ovary – jug-like structure that contains 1 or more ovules Ovule – forms the seed of flowering plants Types of Flowers Types of Flowers 1. Complete Flower 2. Incomplete Flower  Has the four floral parts: sepals, petals,  Lacks one or more of the four main whorls stamens, and carpel Types of Flowers 3. Perfect/Bisexual 4. Imperfect/Unisexual  With both stamens and carpels  Has stamen or carpel but not both Staminate flower Pistillate/Carpellate flower Types of Flowers 5. Regular flower 6. Irregular flower  Petals are of similar shape that radiate  Have whorls either with dissimilar part; from the center and are equidistant from parts do not radiate from the center and each other. are not equidistant from one another Monoecious vs Dioecious A. Monoecious o One in which the male and female structures are borne on the same plant but not in the same flower. o Example: Corn – Zea mays Squash – Cucurbita maxima B. Dioecious o One in which the male and female reproductive organs are on separate plants o Example: Papaya – Carica papaya Types of Ovary Types of Ovary A. Inferior Ovary B. Superior Ovary  Ovary is found below the point of  Ovary is found above the point of attachment of the floral parts attachment of the floral parts Types of Flower (Ovary Position in Relation to Floral Parts) 1. Hypogynous Flower – floral parts are attached below the ovary; with superior ovary 2. Epigynous Flower – ovary is embedded and the floral parts seem to arise from the top of the ovary; inferior ovary 3. Perigynous flower – floral parts are fused (hypanthium) and surrounding the ovary but not fused with it. Pollination  Refers to the transfer of pollen from anther (stamen) to stigma (carpel)  Self-pollination - within the same flower; different flowers on the same plant  Cross pollination – where pollen is transferred to a flower of another plant Agents of Pollination Wind Water Animals (insects, birds, bats)  Animal-Pollinated Flowers – with showy petals, scent, nectar  Wind-Pollinated Flowers – with inconspicuous flowers, do not have large, colorful petals, without scent and without nectar; with large/feathery stigmas  Types of Inflorescence Inflorescence – flowers borne in clusters or groups 1. Spike – flowers are sessile along a simple undivided axis/rachis 2. Raceme/Racemose – similar to spike but the flowers are pedicelled. 3. Panicle/Paniculate – where the axis is divided regularly into branches, bearing 2 or more flowers. 4. Umbel/Umbellate – where the flowers are pedicelled and all spring from the apex of the peduncle. 5. Head/Capitate – flowers are sessile and crowded in a globose mass Inflorescence – flowers borne in clusters or groups 6. Corymb/Corymbose – where the branches although starting from different points, all attain the same level; outer flowers opening first. 7. Cyme/Cymose – a group of flowers in which the end of each growing point produces a flower, so new growth comes from the side and the oldest flowers are at the top. 8. Fascicle – where the flowers are sessile or pedicelled and crowded usually axillary. 9. Catkin/Ament – slim, cylindrical flower cluster, often drooping, usually dense, scaly spike. 10. Spadix – a dry or fleshy spike with small flowers, commonly surrounded by an enveloping organ (spathe)  End I do not own the images and videos in this presentation. Credits are to the owners References Arimura, G. and M. Maffei. 2016. Plant Specialized Metabolism: Genomics, Biochemistry and Biological Functions. CRC Press. Balfour, A. 2018. Plant Science: Biology and Growth. ML Books International. Berg L.R. 2007. Introductory Botany: Plants, People and the Environment. 2nd Ed. Cengage Learning. Campbell, NA, Reece KB, Urry LA, Cain ML, Wassermann SA, Minorsky PV, Jackson, RB. 2010. Biology. 9th ed. Pearson. Hodson MJ and JA Bryant. 2012. Functional Biology of Plants. Wiley-Blackwell Publisher. Hulasare, R. 2016. Functional Biology of Plants. Scitus Academics. Mader, S. 2011. Essentials of Biology. 3rd Edition. McGraw Hill Companies Solomon, EP, Berg, LR, Martin DW. 2011. Biology 9th ed. Thomson Brooks/Cole Starr C, Taggart R, Evers C, & L. Starr. 2013. Biology: The Unity and Diversity of Life. 14th ed. Thomson Brooks/Cole