1. SC: Asteridae Order: Asterales Family: Asteraceae “Composites, Sunflowers”  1. 22,000 species in 900 genera  2. Flowers (florets) are typically arranged in HEADS. Expanded Receptacle; florets epigynous; entire Head surrounded by an involucre of bracts – phyllaries; head is support by a flower stalk called the peduncle; inferior  Pappus – bristles or scales (modified calyx)  Corolla – coalescence of petals  Stamen – 5 coalescent around style  Pistil – one; 2 stigma lobes

2. SC: Asteridae Order: Asterales Family: Asteraceae “Composites, Sunflowers”  Pappus – bristles or scales (modified calyx)  Corolla – coalescence of petals  Stamen – 5 coalescent around style  Pistil – one; 2 stigma lobes  3. Ray Flowers – 3 of the coalesced petals elongate into a ligule.  4. Great variablity! Sterile, pistilate, staminate, perfect….

3. Tribes  Chicory Tribe – 1. Ray flowers only 2. Milky sap Lactuca “wild lettuce”, Taraxicum “dandelion”, Chicorium “chicory”

4. Tribes  Ragweed Tribe - Monoecious; staminate and pistillate flowers on same plant Ambrosia trifida “giant ragweed”, Ambrosia artemisifolia “small ragweed”

5. Tribes  Aster Tribe - Style branches flattened in middle…. Solidago “goldenrods”, Aster “asters”

6. Tribes  Sunflower Tribe - 1. Both disc and ray flowers 2. Usually a crown of hairs at base of stigma 3. Pappus mostly bristle-like Helianthus “sunflowers”, Chrysanthemum “ox- eyed daisy”

7. Tribes  Snakeroot Tribe - 1. disc flowers only 2. leaves mostly opposite Eupatorium rugosum “white snakeroot”, Liatris “blazing star”, Eupatorium purpureum “Joe Pye weed”, Eupatorium altissimum “tall thoroughwort”

8. Tribes  Ironweed Tribe – 1. Disc flowers only 2. Anthers sagittate 3. Stigma lobes long and pointed Veronia “ironweed”

9. Tribes  Thistle Tribe – Receptacle with a spiny involucre of bracts Cirsium vulgare “bull thistle”, Carduus nutans “musk thistle”