stem

A comprehensive vocabulary flashcard set covering shoot morphology, primary stem organization, modified stems, plant life cycles, and secondary stem features based on lecture slides.

Shoot

The structurally complex plant body consisting of nodes, internodes, leaves, and axillary buds, produced by a shoot apex that produces leaves and lateral shoots.

Nodes

The region on a plant stem where one or more leaves are attached.

Internodes

The stem region situated between two successive nodes.

Principal Stem Functions

The two primary roles of plant stems: providing structural support for leaves and conducting water, minerals, and manufactured leaf substances throughout the plant.

Phytomere

A repetitive structural unit of a shoot consisting of a leaf, a node, an internode, and an axillary bud.

Anticlinal divisions

Cellular divisions that occur perpendicular to the outer surface of the plant tissue.

Periclinal divisions

Cellular divisions that occur parallel to the outer surface of the plant tissue.

Aesculus hippocastanum

The scientific name for horse chestnut, whose young shoots are protected by bud scales.

Tilia americana

The scientific name for basswood, which exhibits primary stem growth where the vascular system appears as a continuous hollow cylinder around the pith.

Medicago sativa

The scientific name for alfalfa, which displays primary stem growth characterized by discrete vascular bundles forming a single ring around the pith.

Ranunculus

The genus name for buttercup, whose vascular bundles contain primary xylem, primary phloem, companion cells, and a bundle sheath.

Zea mays

The scientific name for maize, which has primary stem growth featuring numerous vascular bundles scattered throughout the ground tissue without a distinct pith.

Ulmus

The genus name for elm, characterized by a primary vascular system of discrete vascular bundles encircling the pith.

Rhizome

A subterranean plant stem that grows horizontally from axillary buds, sending out roots and shoots from its nodes.

Tuber

A swollen, fleshy, usually underground outgrowth of a stem or rhizome bearing buds from which new plant shoots arise, such as a potato.

Runner (or Stolon)

A surface plant stem developing from axillary buds that grows horizontally above ground and sends out roots and shoots from its nodes.

Bulb

A short, modified underground stem surrounded by fleshy modified leaves that store food for the shoot within.

Corm

An underground storage stem lacking fleshy leaves that allows plants to survive winter, drought, or heat.

Tendril

A modified stem that provides climbing support by growing faster on one side to spin around structure.

Thorn

A modified stem that takes the form of a sharp woody structure.

Prickle

A modified dermal structure functioning as defense against herbivores.

Spine

A modified leaf adapted for defense against large herbivores.

Cladophyll

A flattened stem that resembles and functions as a leaf, commonly found in water-storing succulents.

Annuals

Plants that complete their lifecycle within a single season and survive as dormant seeds.

Biennials

Plants that live for two seasons, forming roots, a short stem, and a rosette of leaves in the first year, and flowering, fruiting, forming seed, and dying in the second.

Perennials

Plants that live year after year.

Secondary Growth

Plant stem thickening that results from the activity of two lateral meristems: the vascular cambium and the cork cambium.

Lenticels

Slit-like external features on woody stem bark that allow for gas exchange.

Bark Beetles

Small (< 1/4 inch) hard-bodied beetles in California conifers that bore into protective bark to lay eggs in the moist phloem, disrupting nutrient transport.