North American Wildland Plants, Second Edition: A Field Guide

Glossary

a- prefix meaning without abaxial on the side away from the axis; lower surface abortion failure of an organ or structure to develop; early termination of pregnancy resulting in the death of the embryo or fetus abrupt changing sharply or quickly, rather than gradually absent not present; never developing acaulescent stemless; without an above-ground stem or apparently so acerose needle-shaped; acicular achene a dry, one-seeded, indehiscent fruit with a relatively thin wall in which the seed coat is not fused to the ovary wall except at one point at the base acicular needle-shaped; acerose acidic soil with a low pH (less than 5.5) acidulous acid in taste; sour acorn a dry fruit seated in or surrounded by a hard, woody cupule of indurate bracts, as in the genus Quercus actinomorphic symmetrical, regular; divisible into equal halves in two or more planes (contrast with zygomorphic) acuminate gradually tapering to a sharp point and forming concave sides along the apex; compare with acute acute tapering to a pointed apex with more or less straight sides; sharply pointed; angle less than 90° adaxial on the side nearest the axis; upper surface addicted having a compulsive need for a habit-forming substance adnate attached or grown together; fusion of unlike parts, such as palea and caryopsis in the genus Bromus aggregated densely clustered alkali a soil with a high pH (8.5 or higher) and high exchangeable sodium content (15% or more), normally interferes with the growth of most species alkaloid any of numerous nitrogen-containing organic bases, many naturally occurring secondary metabolites in plants, which may be toxic to animals alluvium mineral or soil material deposited by running water alpine mountainous regions or areas alternate located singly at each node; not opposite or whorled Glossary 436 ament a dense spike or raceme with many small, usually naked, flowers; a catkin, as in the genus Populus androgynous with both pistillate and staminate flowers, the staminate flowers are borne above the pistillate flowers in the same inflorescence -angled suffix meaning a corner angular forming an angle; with one or more angles annual within one year; applied to plants that do not live more than one year anterior in front of; in a flower, the side away from the axis and adjacent to the bract anther the part of a stamen in which pollen develops anthesis the period of flowering; period during which pollination occurs antidote a remedy to counter the effects of a toxic substance antrorse directed upward or forward; opposed to retrorse apetalous without petals apex the tip or distal end apical relating to the apex apiculate ending in an abrupt, sharp point apomixis process of setting seed without fusion of gametes appressed lying against an organ; flatly pressed against aquatic growing in, on, or near water arching curved like an arch arcuate curved like a bow or arch aristate awned or tapering; a very long, narrow apex armed having sharp thorns or spines aromatic fragrant or having an odor; bearing essential oils arroyo a gully or channel; a watercourse in an arid region articulate jointed, provided with nodes; separating clearly at maturity articulation a joint or point of attachment ascending growing or angled upward; obliquely upward astringent able to draw together soft tissues; styptic asymmetrical not symmetrical; not divisible into equal halves attenuate gradually narrowing to a slender apex or base auricle ear-shaped lobes, such as those that occur at the base of leaf blades of some grasses awl-shaped narrow and sharp pointed; gradually tapering from a narrow base to a pointed apex; subulate awn a slender bristle at the end, on the back, or on the edge of an organ; in grasses, the extension of a vein beyond the leaf-like tissue awn column undivided portion of the awn below the branches, such as in the genus Aristida awnless without awns axil angle between an organ and its axis 437 axillary growing in an axil axis the central or main longitudinal support upon which parts are attached balsam aromatic and resinous substances from plants containing benzoic or cinnamic acid banner upper petal (standard) of the papilionaceous flower in the fabaceae barb a short, rigid projection barbed furnished with retrorse projections bark exterior covering of a woody stem or root; tissues lying outside the cambium barren unproductive sites, usually with shallow soils basal located at or near the base of a structure, such as...