Morphology of Flowering Plants

Functions of roots Absorption of water and minerals Anchorage of plant parts Storage of reserved food material Synthesis of plan growth regulator Which type of root system is present in Gymnosperms & Angiosperms ? Gymnosperms have taproot system Angiosperms are divided into dicots and monocots Majority of the angiosperms have taproot system Dicots have taproot system and monocots have fibrous root system What are Velamen Roots? Roots of epiphytic plats like orchids are called velamen roots. {epi = above} {phyta = plant} They have special tissue called epithem tissue which is hygroscopic in nature {absorb water} These roots are aerial & adventitious roots Example: - Vanda Velamen Roots Phytohormone Plant Growth Regulator also known as Phytohormone or PGR Functions of Parts of Roots Root cap Protects the tender root tip Region of meristematic Activity Cells divide repeatedly, so helps in growth Region of elongation Responsible for growth of roots in length Region of maturation Some of the epidermal cells form fine hair like structures called hair roots. Root Hair Absorbs water and mineral from the soil Taproot and Fibrous Root The roots present in sweet potato are fibrous roots which falls under adventitious roots. Some lateral roots (Adventitious root ) become swollen due to the storage of reserve food Example: - Sweet Potato Here, the reserve food is stored only in certain parts of the roots The diagram shows the roots of the Asparagus plant. Few roots of the plant growing in swampy regions grow vertically upwards These roots are called pneumatophore/ Breathing roots/ Respiratory roots A small opening called pneumathodes helps in the exchange of gasses The examples are given in the diagram on the right It bears branches, leaves, fruits, and flowers Conducts water and minerals Helps in photosynthesis In some plants, it performs the function of storage, protection, and vegetative propagation The products formed during photosynthesis process are called photosynthates The main product is glucose Glucose is stored in the form of starch Starch is converted into sucrose and is delivered to the growing parts of the plant Underground stems of potato, ginger, turmeric, zaminkhand, Colocasia stores food and acts as organ of perennation under favourable conditions. Stem tendrils developed from axillary bud helps the plant to climb. Example: - Cucumber, watermelon, pumpkins, and grapevines. Axillary bud of the stem may get modified into pointed, woody thorns for protection from browsing animals. Example: - Bougainvillea, citrus Some plants growing in arid regions modify their stem into flattened {opuntia} or cylindrical {euphorbia} to perform photosynthesis In some plants like grass and strawberry, underground stem spreads into new niches and the older one die forming a new plant In plants like mint and jasmine, a slender lateral branch arises from the main axis and after growing vertically for some distance, arches down. In aquatic plants like Eichhornia and Pistia, a lateral branch with nodes and internodes bearing roots and leaves is found In banana, pineapple and Chrysanthemum, a lateral branch originates from basal and underground portion of the stem, grow horizontally beneath and then come out obliquely upward giving rise to the leafy shoot Leaf has three main parts: i. Leaf base ii. Petiole {Leaf Stalk} iii. Lamina It helps in photosynthesis It helps to hold the blade to light It helps in cooling the leaf It’s the point of attachment of leaf to stem In some leguminous, the leaf base may become swollen which is called pulvinus Helps in positioning of leaf Helps in sleep and shock pressures Provide rigidity to the leaf blade Acts as a channel for the transport of water, minerals, and food materials Arrangement of veins and veinlets in a lamina Arrangement of leaves on stem or branch Leaves get converted into tendrils for climbing Example: - Pea and Grape Leaves get modified into spines Example: - Cacti Leaves become fleshy for storage of food Example: - Onion and garlic In some plants like the Australian Acacia, leaves are small and short lived. Petiole expands, becomes green and performs photosynthesis Leaves modify into special structures to trap insects. Example: - Pitcher plant, Venus’s fly trap The arrangement of flowers on the floral axis is termed as inflorescence. A flower bearing branch or a system of branches The flower is a modified shoot apical meristem where the shoot changes to floral meristem. Internodes do not elongate, and the axis get condensed, and the shoot tip transform into a flower. Calyx: - Sepals Corolla: - Petals Stamens: - Androecium Pistil: - Gynoecium In some flowers like the Lily, the calyx, and the corolla fuse together to form tepals Both androecium and gynoecium are present in the same plant Example: - Hibiscus, Mustard Either androecium or gynoecium is present in the flower Example: - Papaya, Cucumber, Pumpkins The number of appendages present in each whorl is called Merosity Mostly members of calyx and corolla will be considered in floral Merosity i. When the floral appendages are in multiple of three. Seen in flowers of monocot plants Trimerous – 3 Floral members – Liliaceae {Advanced} ii. Tetramerous – 4 Floral members – Cruciferae/ Brassicaceae iii. When floral appendages are four or five. Seen in flowers of dicot plants Pentamerous – 5 Floral members – Solanaceae Fabaceae Malvaceae Reduced leaves forming bracts found at the base of the flower Example: - Vanilla, mustard, sunflower No bracts China rose, lily, tulip Green leaf like structure United sepals {Gamosepalous} Example: China rose Free sepals {Polysepalous} Example: - Rose Protects the flower in bud stage Usually, bright coloured to attract the insects for pollination United/ fused petals {Gamopetalous} Example: - China rose, Petunia Free petals {Polypetalous} Example: - Rose The mode of arrangement of sepals and petals in a floral bud with respect to other members of the same whorl Stamens attached to petals Example: - Brinjal Stamens attached to perianth Example: - Lily Free stamens In one group – Monoadelphous Example: - China rose In two bundles – Diadelphous Example: - Pea In more than two bundles – Polyadelphous Example: - Citrus A sterile stamen Stamens of variable length are seen in salvia and mustard Fused ovaries Example: - Mustard, China rose, tomato Free ovaries Example: - Lotus, rose Arrangement of ovules within the ovary After fertilisation, the ovaries mature into a fruit and the ovules develop into seeds. Ovaries after fertilisation develop into fruit Epicarp is the thin brown layer on coconut Mesocarp is the edible part Pericarp is fleshy and juicy and includes epicarp, mesocarp and endocarp Fruits developed from monocarpellary, superior ovary & single seeded Example: - Mango & Coconut Fruit developed from ovary without fertilisation is called parthenocarpic fruit Example: - Banana Ovules after fertilisation develop into seed Opening through which the seeds respire and take water Scar on seed coat represent point of attachment of seed to fruit The outer covering of endosperm separates the embryo by a protein layer called aleurone layer Embryo is small and situated in a groove at one end of the endosperm It consists of a large shield shape cotyledon is called scutellum and a short axis with a plumule and a radicle The plumule is enclosed in a sheath called coleoptile and radicle called coleorhiza respectively Symbolic representation of floral parts of the flower Diagrammatic representation of floral parts of the flower K – Calyx C – Corolla Br – Bracteate A – Androecium Ebr – Ebracteate G – Gynoecium ♂ - Male Flower ♀- Female Flower ( ) – Fusion Of Floral Parts G – Superior Ovary ⚥ - Bisexual Flower – – G – Inferior Ovary - Actinomorphic Flower P – Perianth % - Zygomorphic Flower It is a large family, commonly called as the ‘potato family’. It is widely distributed in tropics, subtropics, and even temperate zones Plants mostly herbs, shrubs, and rarely small trees Stem: herbaceous rarely woody, aerial; erect, cylindrical, branched, solid or hollow, hairy or glabrous, underground stem in potato (Solanum tuberosum) Leaves: alternate, simple, rarely pinnately compound, exstipulate; venation reticulate Inflorescence: Solitary, axillary or cymose as in Solanum Flower: bisexual, actinomorphic Calyx: sepals five, united, persistent, valvate aestivation Corolla: petals five, united; valvate aestivation Androecium: stamens five, epipetalous Gynoecium: bicarpellary obligately placed, syncarpous; ovary superior, bilocular, placenta swollen with many ovules, axile Fruits: berry or capsule Seeds: many, endospermous Floral Formula: ⊕ ⚥ K (5) C (5) A5 G – (2)