Flower = a short, determinate shoot bearing highly modified leaves, some of which are fertile (i.e., bearing either microsporangia or megasporangia), with the megasporangia in carpels Review: flowers and flower parts

Flower REPRODUCTIVE STRUCTURE OF ANGIOSPERMS – Evolutionary requirement to reproduce by sexual means. Pollen transfer and seed dispersal needed. MODIFIED FOLIAR APPENDAGES – all function together to form the reproductive organ known as the FLOWER. MODIFICATIONS OF LEAVES – All floral organs are modified LEAVES. Four terminal WHORLS of modified leaves: - Two outermost whorls are sterile (non-meiotic tissues) - Two innermost whorls (sporophylls) are “fertile” with tissues capable of undergoing meiosis SPOROPHYLLS – those modified leaves with meiotic capacity. - Microsporophylls – stamens – produce pollen in anthers - Megasporophylls – carpels – produce eggs in ovules

Figure 4.16 from the text

Floral Parts: Major whorls pistil - gynoecium stamens - androecium petals - corolla sepals - calyx receptacle

Figure 4.21 from the text

Superior, Hypogynous

Superior, Perigynous Floral cup (= hypanthium) present but not fused with the gynoecium

Inferior = Epigynous Hypanthium fused to gynoecium, sometimes extending above it into a conspicuous floral tube.

In a few special cases, the Cactaceae being the main example, epigynous flowers have a hypanthium derived mainly from receptacle tissue.

Rosids – Part 4: Eurosids II - Brassicales - Malvales - Sapindales Spring 2010

“Lower” Core tricolpates Rosids (Eurosids II) (Eurosids I) “Basal” rosids Figure 9.3 from the text

Core Eudicots: The Rosids Lecture 4 “Basal” Rosids: Order Vitales Eurosids I (Fabids): Order Malpighiales Order Cucurbitales Order Fabales Order Rosales Order Fagales Order Myrtales Eurosids II (Malvids) Order Brassicales Brassicaceae - Mustards Order Malvales Malvaceae – Mallows, cotton, chocolate Order Sapindales Sapindaceae – Maples, lychee Rutaceae – Citrus Anacardiaceae – Mangoes, cashews, poison ivy

Eurosids II: Brassicales: Brassicaceae (‘Cruciferae’ - The Mustard Family) Cosmopolitan, most diverse in the Mediterranean region, SW Asia, and western North America Herbs, shrubs or trees; (sometimes herbs); glucosinolates (mustard oils) present in all taxa Diversity: 4,130 species in 356 genera Flowers: Receptacle prolonged into a gynophore (short to long); Sepals 4; petals 4 (cruciform); stamens 6, all + equal or 2 shorter and 4 longer (tetradynamous); carpels usually 2, connate, superior ovary; fruit is a berry or capsule; if dehiscing by splitting into 2 valves, a silique Significant features: 4-merous flowers forming a cross; often pioneers after disturbance Special uses: Many important food plants – cabbage, broccoli, cauliflower, brussels sprouts, kohlrabi (Brassica oleracea), turnip (Brassica rapa), mustards (Brassica spp.), horseradish (Armoracia rusticana), and a wide range of ornamentals Required taxa: Brassica

Brassicaceae cruciform petals silique - silicle tetradynamous stamens

Arabidopsis thaliana The model plant of choice for much of molecular biology.

-annuals or biennials -at least the lower leaves deeply pinnatifid, lyrate or pinnate -racemes without bracts -sepals erect during anthesis -petals yellow -ovary and silique with a prominent beak Brassicaceae: Brassica

Brassica oleracea

Eurosids II: Malvales: Malvaceae (The Mallow Family) Cosmopolitan Trees, shrubs, lianas or herbs; vegetative parts with mucilage; leaves palmately veined and lobed or palmately compound Diversity: 2,330 species in 204 genera Flowers: Sepals & petals 5; stamens 5 to many, monadelphous or polydelphous; carpels 2 to many, connate, superior ovary; fruit usually a loculicidal capsule, also berry, nut, schizocarp, or drupe Significant features: flowers often associated with conspicuous bracts forming an epicalyx; nectaries of densely packed, multicellular glandular hairs, usually on sepals Special uses: cotton (Gossypium), cacao or chocolate (Theobroma), durian (Durio), balsa wood (Ochroma); many ornamentals, e.g. hibiscus (Hibiscus) Required taxa: Hibiscus, Gossypium

Polydelphous stamens Monadelphous stamens Malvaceae

Malvaceae: Hibiscus -herbs or shrubs -epicalyx of a circle of several bractlets -filament column bearing anthers for much of its length -styles distinct -fruit a 5-locular loculicidal capsule -seeds 2-several per locule, kidney-shaped

Malvaceae: Gossypium -subshrubs to shrubs -epicalyx of large, cordate, toothed bracts -styles united -fruit a 3-5-locular loculicidal capsule -seeds + globular, often with hair (lint)

Eurosids II: Sapindales: Sapindaceae (The Maple Family) Mainly tropical and subtropical, a few diverse in the temperate zone (e.g., Acer, Aesculus) Trees, shrubs or lianas with tendrils Diversity: 2,215 species in 147 genera Flowers: Usually unisexual; sepals & petals 4-5, petals often clawed, with more or less basal appendages adaxially; usually an extrastaminal nectar disk present; stamens 8 or fewer (rarely up to 12), filaments usually hairy or papillose; carpels 2 or 3, connate, superior ovary; fruit a capsule, berry, or schizocarp; seeds with a deep fold or pocket in the seed coat Significant features: cyclopropane amino acids Special uses: lumber, maple syrup (Acer saccharum); many ornamentals; tropical fruits (longan, lychee, rambutan) Required taxa: Acer

Sapindaceae phylogeny SAP HIPP ACER SAP Chemistry Appendaged petals Curved embryo w/ seed coat “pocket” 8 or fewer stamens Etc.

Sapindaceae: Acer -trees or sometimes shrubs -leaves opposite, simple and palmately lobed, rarely pinnately or palmately compound -calyx usually 5-lobed -petals 0 or as many as the calyx lobes -ovary with 2 connate, winged carpels, 2 ovules per carpel -fruit a schizocarp, splitting into 2 samaroid mericarps

Eurosids II: Sapindales: Rutaceae (The Citrus Family) Nearly cosmopolitan, primarily tropical to subtropical Trees or shrubs, sometimes with thorns, spines or prickles Diversity: 930 species in 155 genera Flowers: Sepals & petals 4 – 5; stamens 8-10; carpels 4-5 to many, connate, superior ovary; axile placentation; fruit a drupe, capsule, samara, cluster of follicles or modified berry with leathery, glandular rind (i.e., hesperidium in Citrus). Significant features: Aromatic oils chemically complex; simple or compound leaves with pellucid dots containing aromatic ethereal oils Special uses: many desirable fruits - oranges, lemons, limes, tangerine, grapefruit (Citrus), kumquat (Fortunella), several ornamentals, e.g. cork tree (Phellodendron) Required taxa: Citrus

Rutaceae: Citrus -leaves apparently simple, of 1 leaflet -ovary compound, entire or only slightly lobed -fruit a hesperidium

Eurosids II: Sapindales: Anacardiaceae (The Sumac or Cashew Family) Mainly pantropical; some in temperate regions Trees, shrubs, or lianas; well-developed resin canals; leaves usually pinnately compound & alternate Diversity: 600 species in 70 genera Flowers: Usually unisexual; Sepals & petals 5; stamens 5- 10; carpels usually 3, connate, but usually only 1 carpel fully developed and fertile; superior ovary; fruit is a drupe, frequently flattened and asymmetrical Significant features: Medically-important – poison-ivy (Toxicodendron radicans) and other taxa (Rhus, Metopium) cause contact dermatitis due to oils in plant tissues. Some individuals are even allergic to ‘edible’ taxa. Special uses: mangoes (Mangifera indica), cashews (Anacardium occidentale), pistachio (Pistacia vera); some ornamentals, e.g. Sumac (Rhus) and smoke-tree (Cotinus) Required taxa: Toxicodendron

Anacardiaceae: Toxicodendron T. radicans - Poison Ivy -resins toxic -inflorescences axillary panicles -fruits glabrous, greenish to white