The Reproductive Body: Flowers PBIO 369 Fall 2010

Reproductive Body Shoot Vegetative Body Root

Parts of a Flower

Four whorls of the flower: Set of sepals = Calyx Set of petals = Corolla Set of stamens = Androecium Pistil (or set of pistils) = Gynoecium

A flower that has all four whorls is said to be both complete and perfect.

Japanese knotweed: flowers lack a calyx and are therefore incomplete

Begonia: flowers are imperfect staminate pistillate (This is another way of saying that the flowers are unisexual.)

Red Maple plants are dioecious. staminate dioecious: ‘two houses’ pistillate

Box elder is also dioecious...

Bur-reed plants are monoecious. monoecious: ‘one house’

as is corn.

Petals may be separate ...

or they may be fused

Symmetry Water lily: symmetry is radial

Symmetry orchid: symmetry is bilateral

Gynoecium Structure

The terms carpel and pistil are often used interchangeably, but … Ovary The terms carpel and pistil are often used interchangeably, but …

In a compound pistil, the carpel is a subunit of the pistil In a simple pistil, carpel = pistil

lev70065_05_02.jpg compound pistil simple pistil

Three possibilities for gynoecium structure: One simple pistil per flower (e.g., pea) Two or more simple pistils per flower (e.g., buttercup, strawberry) One compound pistil per flower (e.g., cucumber)

One simple pistil per flower ...

Two or more simple pistils per flower ...

One compound pistil per flower

Placentation

How to determine the number of carpels in a compound pistil? If the placentation is axile, count the number of locules (chambers) in the ovary If the placentation is parietal, count the number of placentae

How to determine the number of carpels in a compound pistil? If the pistil has more than one style and/or stigma, count them If the fruit is dehiscent (opens up), count the number of seams

If ovary is: Flower is: Superior hypogynous Inferior epigynous Half-inferior perigynous

Hypanthium - A floral cup or tube formed by the fusion of the basal portions of the sepals, petals, and stamens, and from which the rest of the floral parts arise.

Pistils Pistils

Liliaceae - the Lily Family

Vegetative attributes: Perennial herbs Stems = bulbs, rhizomes, corms Leaves alternate or basal, simple, entire, parallel-veined

Reproductive Attributes: Ca3 Co3 A6 G(3) or Ḡ(3 Flowers actinomorphic, in spikes, racemes, panicles or umbels. Perianth with 6 petaloid tepals, two similar whorls Androecium of 6 stamens Pistil compound of 3 carpels, 3 locules, single style; ovary superior or inferior Fruit a capsule or berry Floral dagram, Liliaceae

Economic importance: Ornamentals, such as day lilies and tulips Edibles, such as chives, garlic, onion, asparagus, leeks Medicinal uses from aloe and agave Tequila from agave

In recent years, the Liliaceae sensu lato has been split up to yield: Liliaceae sensu stricto (trout lily) Trilliaceae (wake robin) Convallariaceae (Canada mayflower) Alstromeriaceae (alstromeria) Smilacaceae (greenbriar) Alliaceae (wild leeks) Amaryllidaceae (amaryllis) and more

Liliaceae - local flora Trillium grandiflorum White trillium Erythronium americanum Trout lily Clintonia borealis Blue-bead lily Streptopus roseus Rose twisted stalk Maianthemum canadense Canada mayflower

Veratrum viride False Hellebore a toxic member of the lily family

calyx subtended by 2 bracts (that appear to be part of the calyx) calyx ebracteate (it lacks bracts, or, better said, the bracts don’t appear to be part of the calyx)

Saponaria officianalis Caryophyllaceae The Pink Family Ca 5 Co 5 A 5-10 G 2-5 Saponaria officianalis Herbs with opposite leaves and swollen nodes Flowers radially symmetrical Fruit a denticidal capsule Little economic importance ( a few ornamentals, e.g., carnation)