Plant Kingdom Gymnosperm and Angiosperm Overview Evolutionary Development

Plant Kingdom Gymnosperm and Angiosperm

Overview Evolutionary Development of Seed Gymnosperms Evolutionary Development of Seed Life cycle Subclasses of Gymnosperms Angiosperms Life Cycle Monocotyledon Subclasses Dicotyledon Subclasses

Evolutionary Development of Seeds

Evolutionary Development of Seeds Seed contains an embryo already packaged within the seed, and nutritive tissue surrounded by a protective coat. It contains well-developed multicellular young plant with embryonic root, stem, and leaves already formed The parent plant protects and supports the young plant in the seed during its development

Evolutionary Development of Seeds A seed also contains food supply After germination, it is nourished by food stored in the seed A seed is protected by a multicellular coat Seeds and seed plants have been intimately connected with the development of human civilization.

Evolutionary Development of Seeds This development made it possible for seed plants to complete their life cycles in relatively dry environments, compared to those of non-seedproducing vascular plants.

Gymnosperms

Gymnosperms Seed bearing plants that lack the combination of specialized features that characterized flowering plants Gymnosperm also means “naked seed”

Gymnosperms are made up of heterogeneous group of plants characterized by the production of naked seeds. Records indicate that they evolved approximately 300 million years ago from nonseed producing ancestors of the extinct division of Progymnospermophyta, which were fern-like in appearance.

Gymnosperms They lack the folded, marginally-sealed carpels that characterize the flowering plants. The pollen-receptive structures are the ovules rather than the stigmatic portion of the carpels. Most gymnosperms lack xylem, except for gnetophytes.

Gymnosperms Considering the relatively small number of living gymnosperms (about 720 species in 65 genera), they are remarkably diverse in their reproductive structures and leaf types.

Gymnosperms Life Cycle

Gymnosperms CLASSES Cycadopsida Gingkopsida Gnetidopsida Pinidopsida

Gymnosperms Cycadopsida

Gymnosperms Cycadopsida Cycads are an ancient group of seed plants with a crown of large compound leaves and a stout trunk. All sp. of cycads are dioecious, producing microsporangial (male) cones and ovulate (female) cones at the terminal end of the trunk (which is unbranched).

Gymnosperms Cycadopsida Cycads have palm-like leaves that bear no resemblance to leaves of other living gymnosperms. Under favorable conditions, cycads usually produce one crown of leaves each year.

Gymnosperms Gingkopsida

Gymnosperms Gingkopsida It is the oldest known genus (and species) of living trees. It is exclusively dioecious and deciduous. It has distinctive fan-shaped leaves with dichotomous venation

Gymnosperms Gingkopsida The seeds of Ginkgo include a massive integument (outer coating of an ovule; later becoming testa of a seed) that consists of a fleshy outer layer, a hard, stony middle layer, and an inner layer that is dry and papery. Paired ovule, not in cones, produced at the tips of short branches on the female trees.

Gymnosperms Gnetopsida

Gymnosperms Gnetopsida This group includes some of the most distinctive, and bizarre, seed plants. 3 generas: Ephedra, Gnetum and Welwitschia They have flower-like compound strobili.

Gymnosperms Gnetopsida They have vessels in secondary xylem. They have double fertilization. (However, this double fertilization does not result in the formation of endosperm. Instead, the diploid cell from fertilization by the second sperm disintegrates).

Gymnosperms Pinopsida

Gymnosperms Pinopsida The informal name of the group, conifers, signifies plants that bear cones, even though other members of the gymnosperms also include cone-bearing species. The genus Pinus, by far the largest genus within the conifers, consists of about 100 spp.

Angiosperms are seed-bearing vascular plants. Their reproductive structures are flowers in which the ovules are enclosed in an ovary, it can be found in almost every habitat from forests and grasslands to sea margins and deserts.

Angiosperms

Angiosperms MONOCOT DICOT Embryo with single cotyledon Embryo with two cotyledons Pollen with single furrow or pore Pollen with three furrows or pores Major leaf veins parallel Major leaf veins reticulated Flower parts in multiples of three Flower parts in multiples of four or five Stem vascular bundles scattered Stem vascular bundles in a ring Roots are adventitious Roots develop from radicle Secondary growth absent Secondary growth often present

Angiosperms MONOCOT SUBCLASSES Alismatidae Arecidae Commelinidae Lilidae

Angiosperms Alismatidae The subclass is typically apocarpous and aquatic. Flowers can be showy or highly reduced. The vascular system is usually not well lignified and often much reduced, with vessels restricted to roots if present.

Angiosperms Butomus umbellatus (Flowering rush)

Angiosperms Arecidae The Arecidae are morphologically and ecologically diverse and include the smallest known angiosperm - the aquatic Wolffia - as well as giant palms.

Angiosperms Palm

Angiosperms Commelinidae The Commelinidae has been defined by the absence of septal nectaries, with pollination mediated by pollen gathering bees or by wind. Floral reduction associated with adaptation to wind pollination is a prevalent trend in the subclass.

Angiosperms Oplismenus hirtellius (basketgrass)

Angiosperms Liliidae The Liliidae characteristically, although not always, has showy 3 -merous flowers, with the tepals all petaloid, and they have extensively exploited insect pollination with well-developed nectaries.

Angiosperms Snowdrop (Galanthus nivalis)

Angiosperms DICOTYLEDON (Magnoliopsida) Subclasses Magnoliidae Hamamelidae Caryophyllidae

Subclass Magnoliidae Dicotyledonous plants that retain some primitive anatomic and morphological characteristics and are not closely related to more advanced groups of flowering plants

Subclass Magnoliidae Consists of 8 orders, 39 families, and approximately 12, 000 species The orders, arranged more or less from the most primitive to the most advanced, are Magnoliales, Laurales, Piperales, Aristolochiales, Illiciales, Nymphaeales, Ranunculales, and Papaverales.

Subclass Hemamelidae Consists of 26 families, and about 3, 400 species of angiosperms often referred to as the Amentiferae, or wind-pollinated group.

Subclass Hemamelidae It is defined by a suite of characters correlated with wind pollination (anemophily) generally woody and deciduous; more or less strongly reduced, unisexual flowers that are borne in catkins; smooth pollen; and nut-like fruits with one or few seeds.

Subclass Caryophyllidae Consists of 13 families, and about 11, 000 species of angiosperms - the bulk of the subclass often referred to as the Centrospermae.

Subclass Caryophyllidae It is a distinctive group usually defined by the presence of beta lain pigments rather than anthocyanin, free-central (hence the name "Centrospermae") or basal placentation in a compound ovary, and an impressive list of anatomical and embryological features.

Subclass Caryophillidae Most members are herbaceous, with woody species possessing anomalous secondary growth. Adaptation to xeric environments with stem succulence and the evolution of C 4 and CAM photosynthesis is common in the subclass.

References https: //faculty. unlv. edu/landau/gymnosperms. htm http: //www. ucmp. berkeley. edu/seedplants/cycadophyta /cycads. html http: //www. theplantlist. org/browse/A/ http: //www. ucmp. berkeley. edu/glossary/gloss 8/monoco tdicot. html http: //botit. botany. wisc. edu/courses/systematics/Phyla/ Magnoliophyta/Alismatidae. html http: //botit. botany. wisc. edu/courses/systematics/Phyla/ Magnoliophyta/Liliidae. html

References https: //www. britannica. com/plant/Magnoliidae http: //botit. botany. wisc. edu/courses/systematics/Phyla/ Magnoliophyta/Hamamelidae. html http: //botit. botany. wisc. edu/courses/systematics/Phyla/ Magnoliophyta/Caryophyllidae. html