Lateral Roots - secondary roots that grow from a larger root

Fibrous Roots - primary root either never existed or ceases to elongate

Root hairs - protrusion of epidermis that develop on the root just behind the zone of elongation.

Zone of maturation - where enlarged cells undergo changes to become the specialized tissues of epidermis (water/mineral absorption), cortex (food storage, movement of water from epidermis), and vascular system (located at core of root, conducts food and water

Zone of elongation - behind tip where cells increase in size through food/water absorption to push root through soil

Meristem - Area of cell division and growth protected by root cap

Root cap - consists of cells that are soughed off as root grows through soil

Typical (stems, trunks, branches, stalks)

Wood plant stem

Herbacious dicot stem

External features

Buds - undeveloped shoot from which leaves or flower parts grow

Leaf Structure

Simple

Dry

spurs - short, stubby side stems from main stem. Common on fruit bearing trees (where fruit will grow).

thorns - can be single (cockspur hawthorn), branched (honeylocust), or modified leaves (cactus)

crowns - compressed stems having leaves and flowers on short internodes (strawberries, dandelions, African violets)

stolons - horizontal fleshy or woody stems that lie along the top of the ground (strawberry runners, bermudagrass)

tubers - thickened, fleshy underground stems (potatoes - eyes are actually nodes with a cluster of buds))

rhizomes - similar to stolons, generally grow underground rather than above it

corms - solid, swollen stems with dry, scale-like leaves on the outside (gladiolus). Shaped somewhat like a bulb without fleshy scales

forms framework that supports leaves, buds, flowers, and fruit

blade - expanded thin structure ; most prominent part of leaf

stipule - small appendages at base of petiole. Usually in pairs and soon shed.

leaflet - Small leaflike structure. Several leaflets make up a compound leaf

parallel - veined: Numerous veins that run essentially parallel to each other. Most monocots have prallel venation.

Net-veined or reticulate-veined: Veins that branch from the main rib or ribs and then subdivide. May be palmate or pinnate

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Cotyledons (seed leaves) - leaves of the embryonic plant. Serve as storage organs to feed the germinating seedling while true leaves develop.

Spines and Tendrils - protect plant or assist in supporting the stems

Storage leaves - found in bulbous plants and succulents; serve as food storage organs containing starch and water.

Bracts - Specialized leaves often brightly colored to attract pollinators (dogwoods, poinsettias)

Leaf arrangement and attachment

sepals (collectivelly called the calyx) - small, leaflike structures at base of flower that protect flower bud. Highly colored are called tepals (daylily).

petals (corolla) - May contain fragrant oils or nectar glands.

Complete - has stamens, pistils, petals, and sepals. If one is missing, flower is incomplete.

Perfect - contains functional stamens and pistils. If either is lacking, flower is imperfect.

Pistillate (female) - contains functional pistil or pistils but lac stamens.

Dioecious (int. "two houses") - Male and female flowers on separate plants (holly).

Monoecious ("one house") - Make and female flowers on same plant. Can have bisexual flowers or separate pistillate and staminate blossoms. Some bear male flowers early then later develop both (cucumber, squash).

endosperm - built-in food suply for embryo. Made of proteins, carbs, or fats.

seed coat (testa) - bard outer covering protecting seed from disease and insects. Prevents water from entering seed and causing premature germination.

radicle - contains root apical meristem & develops into root system

hypocotyl - elongates to form lowest part of stem.

cotyledons (seed leaves) - contain food stored for developing plant (mocots have 1, dicots have 2)

epicotyl - contains shoot apical meristem & develops into shoot system.

Aggregate

Multiple - Originate from a tight cluster of separate, independent flowers borne on a single structure (pineapple, sunflower, corn)