Skip Navigation

University of Nebraska–Lincoln

UNL Extension Horticulture

Healing Landscapes, Healthy Crops, and a Safe Environment

Glossary of Horticulture Terms
A, B, C, D, E-G, H-L, M-O, P, Q-R, S, T, U-Z

Habit Same as growth habit.
Half- or sub-shrub A plant with stems that are woody at the base, usually dying back to the woody stems or even back to the ground after severe winters. Suffrutescent.
Hardened A plant condition created by various factors enabling it to withstand environmental stresses; contrast with succulent growth which is very vulnerable to environmental stress and damage.
Hardy Used in the horticultural sense, enduring winter conditions.
Herb A plant dying to the ground at the end of the season; one whose aerial stems are soft and succulent without appreciable parenchymatous xylem tissue, a plant not woody in texture.
Herbaceous Not woody; having no persistent woody stems above ground.
Hesperidium A fleshy berry-like fruit with a hard rind and definite longitudinal partitions. Ex. Orange
Hip The fruit of a rose.
Hippocrepiform Horseshoe-shaped.
Hirsute Pubescent with coarse or stiff hairs.
Hoary With a close white or whitish pubescence.
Husk Outer covering of a fruit or seed.
Hybrid A plant resulting from a cross between two or more other plants which are more or less alike.
Imbricate Said of scales which overlap like shingles; the opposite of valvate in which the scales meet along a line without overlapping.
Imperfect flower A flower that lacks either stamens (pollen producing structures) or pistils (seed producing structures).
Incised Cut by sharp and irregular incisions more or less deeply, but intermediate between toothed and lobed.
Included Not protruding as stamens not projecting beyond a corolla; as opposed to exserted.
Incomplete flower One which lacks any one or more of these parts; calyx, corolla, stamens, and pistils.
Indehiscent Not opening, as applied to fruits.
Indeterminate Said of those kinds of inflorescence whose terminal flowers open last, hence the growth or elongation of the main axis is not arrested by the opening of the first flowers.
Indurate Hardened.
Inequilateral With unequal sides.
Inflorescence A flower cluster.
Infra- Below.
Internode The part of a stem between two nodes.
Involucrate With an involucre or cluster of bracts.
Involucre A cluster of modified leaves about a flower cluster.
Jointed Having nodes or points of real or apparent articulation.
Juvenile An early phase of plant growth, usually characterized by non-flowering, vigorous increase in size, and often thorniness.
Keel A ridge on the back of a leaf or bud scale.
Key A small indehiscent fruit with a wing.
Knees Pointed or dome-like outgrowths from cypress roots rising above the water.
Lactiferous Milky.
Lanceolate Shaped like a lance-head, as applied to leaves.
Lateral Said of buds which appear along the sides of the twig; borne at or along the side.
Lateral bud A bud borne in the axil of a previous season’s leaf.
Latex Milky sap.
Leader The primary or terminal shoot; the trunk of a tree.
Leaf The foliage appendages of the stem, though not always serving as foliage; sometimes metamorphosed into a spine (barberry), or tendril (clematis), or reduced to a scale (juniper). Leaves originate at and mark the node or joints of the stem. Buds normally occur in the angles or axils above leaves and are correspondingly alternate, opposite or whorled on the stem.
Leaf scar Scars from which leaves have fallen. They usually occur characteristically either singly (alternate) or paired (opposite) or in groups of more than 2 (whorled) at each node. Leaf scars differ greatly in size and shape, and offer some of the best winter characteristics. The points where woody strands of vascular tissue passed up into the leaf are usually evident, and are called bundle scars or bundle traces. Typical leaf scars are essentially at the level of the stem; but they are raised o a pronounced base or leaf cushion in some cases, or the buds are covered by an articular membrane in other.
Leaflet One of the divisions of a compound leaf.
Legume A pod; the characteristic fruit of the pea family.
Lenticels Very small wart-like structures, breaking through the bark of most young twigs. Corky in texture and made of loosely packed cells, providing gaseous exchange between the inner tissues of the stem and the atmosphere.
Lignified Woody, hardened.
Ligule 1. A strap shaped organ. 2. A minute projection from the top of the leaf sheath in grasses. 3. The strap shaped corolla in the ray flower of Composites.
Linear Long and narrow.
Lineate Lined; bearing thin parallel lines.
Lined Lightly ridged or ribbed.
Lobed Divided rather deeply, as applied to leaves.
Lustrous Having a slight metallic gloss, less reflective than glossy.