Vegetative Characteristics How can we use these characteristics to help us identify plants?
Plant Habit • Herb– non-woody, usually small • Shrub – woody, multi-stem, less than 8ft tall • Tree – woody, single stem, greater than 8ft tall • Vine – refers to any plant with a growth habit of trailing or climbing.
Leaf Life Span • Evergreen – has leaves in all 4 seasons, always green, normally have thick and waxy leaves/needles • Deciduous – lose leaves during the winter or dry seasons
Simple vs Compound Leaves • Simple - leaves have a single blade. • Compound leaves - have more than one blade on a single petiole. The multiple blades of a compound leaf are called leaflets. • Palmately Compound - leaves have leaflets arranged like the fingers of a hand. • Pinnately Compound - leaves have leaflets arranged on either side of an axis, resembling a feather. • Trifoliolate - leaves have leaflets arranged in threes, like clover.
Leaf Arrangement • Opposite - Two leaves grow opposite each other at each node. • Alternate - One leaf grows at each node. The leaves alternate sides along the stem. • Whorled - Several leaves grow around a single node.
Leaf Shapes • Linear - Narrow from base to tip. • Elliptic - Oval-shaped. • Ovate - Wide at the base and narrow at the tip. • Cordate - Heart-shaped.
Leaf Margins • Entire - The edge of the leaf is smooth. • Serrate - The edge of the leaf is finely toothed. • Lobed - The edge of the leaf is deeply indented.
Special Features • Thorn – Woody, sharp-pointed modified stem; borne in leaf axil or leaf scar • Spines – Woody, sharp-pointed modified leaf or leaf-part • Prickle – Small, sharp, non-woody outgrowth on surface of bark or epidermis (prickles on a rose) • Tendril - Specialized stem, leaf or petiole with a threadlike shape that is used by climbing plants for support, attachment and cellular invasion by parasitic plants, generally by twining around suitable hosts.
Thorn • Spine • Prickle • Tendril