Botany Focused

Lab 3 - Flowers

Sepals / calyx

The outermost floral whorl; protects the flower bud before it opens.

Petals / corolla

The whorl of colored leaf-like structures that attract pollinators.

Pedicel

The stalk that supports a single flower.

Perianth

The collective term for the calyx (sepals) and corolla (petals).

Connation

Fusion of similar floral parts (e.g., petals fused to petals).

Adnation

Fusion of dissimilar floral parts (e.g., stamens fused to petals).

Stamens

The male reproductive organs of a flower, consisting of anther and filament.

Anther

The part of the stamen that produces pollen.

Filament

The stalk that supports the anther.

Pistil

The female reproductive organ of a flower, consisting of stigma, style, and ovary.

Stigma

The sticky tip of the pistil that captures pollen.

Style

The stalk between stigma and ovary through which pollen tubes grow.

Ovary

The base of the pistil containing ovules that develop into seeds after fertilization.

Inflorescence types

The arrangement of flowers on a stem; includes raceme, spike, umbel, panicle, spathe & spadix, corymb, cyme, and capitulum.

Raceme

Flowers on individual pedicels attached along an unbranched axis.

Spike

Flowers attached directly (sessile) to the main axis without pedicels.

Umbel

Flower stalks (pedicels) of equal length arise from a common point, like umbrella ribs.

Panicle

A branched raceme; flowers on branched stalks.

Spathe & spadix

A fleshy axis (spadix) surrounded by a large bract (spathe).

Corymb

Flower stalks arise at different points but reach the same level, forming a flat top.

Cyme

Inflorescence where the central flower opens first.

Capitulum

A dense cluster of sessile flowers on a flattened receptacle (e.g., sunflower head).

Disc florets

The small tubular flowers in the center of a capitulum.

Ray florets

The strap-shaped flowers around the edge of a capitulum.

Pappus

A modified calyx of fine hairs or scales aiding in seed dispersal (e.g., dandelion).

Ligule

The flattened, strap-like corolla of ray florets in the Asteraceae family.

Ovary position

Describes placement of the ovary relative to other floral parts; can be superior or inferior.

Superior ovary

Ovary positioned above the attachment of other floral parts.

Inferior ovary

Ovary positioned below the attachment of other floral parts.

Perfect flower

Flower containing both stamens (male) and pistil(s) (female).

Imperfect flower

Flower lacking either stamens or pistils.

Complete flower

Flower containing all four main parts: sepals, petals, stamens, and pistils.

Incomplete flower

Flower missing one or more of the main floral parts.

Monoecious

Plant with separate male and female flowers on the same individual.

Dioecious

Plant species with male and female flowers on separate individuals.

Lab 4 - Fruit

Compound fruits

Fruits formed from multiple flowers (multiple) or multiple ovaries of one flower (aggregate).

Multiple fruit

Develops from the ovaries of multiple flowers fused together (e.g., pineapple).

Aggregate fruit

Develops from multiple ovaries of a single flower (e.g., raspberry).

Pericarp

The fruit wall derived from the ovary wall; includes exocarp, mesocarp, and endocarp.

Exocarp

The outer skin or peel of the fruit.

Mesocarp

The fleshy middle layer of the fruit wall.

Endocarp

The innermost layer surrounding the seed(s); may be hard or papery.

Locules

The chambers within an ovary that contain ovules or seeds.

Septum

The walls dividing locules within an ovary.

Carpels

The basic units of the pistil; each encloses ovules.

Sutures

The lines or seams where a fruit splits open.

Fleshy fruits

Fruits with a soft, thick pericarp; include berry, pome, and drupe.

Berry

Entire pericarp is fleshy; usually contains multiple seeds (e.g., tomato).

Pome

Fruit with a fleshy outer layer and a papery core (e.g., apple).

Drupe

Fruit with a single seed enclosed in a hard endocarp (e.g., cherry).

Dry fruits

Fruits with a dry pericarp at maturity; may be dehiscent or indehiscent.

Silicle / silique

Long, narrow dehiscent fruits of the mustard family.

Samara

A winged, indehiscent fruit (e.g., maple).

Achene

A small, dry, one-seeded indehiscent fruit (e.g., sunflower seed).

Legume

A dehiscent fruit splitting along two sutures (e.g., pea pod).

Capsule

A dry fruit that splits open in various ways to release seeds (e.g., poppy).

Nut

A one-seeded fruit with a hard, woody pericarp (e.g., acorn).

Follicle

A dehiscent fruit that splits along one suture (e.g., milkweed).

Dehiscent

Fruit that splits open at maturity to release seeds.

Indehiscent

Fruit that does not open at maturity; seeds remain enclosed.

Involucre of bracts

A group of specialized leaves (bracts) surrounding a flower or fruit cluster.

Cupule

A cup-like involucre surrounding a nut (e.g., acorn).

Husk

A dry, leafy involucre enclosing certain fruits or seeds (e.g., corn husk).