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Glossary of Plant Terms
- University of Wisconsin Press
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Glossary of Plant Terms Abaxial. Pertaining to the side of an organ away from the axis. such as the lower surface of a leaf; cf. Adaxial. Abscise. To separate from. Acaulescent. Stemless or apparently so. or with the stem subterranean . Achene. A hard. dry. indehiscent. one-seeded. one-locular fruit. Actinomorphic. Descriptive of a flower or set of flower parts which can be cut through the center into equal and similar parts along two or more planes; radially symmetrical; regular. Acuminate. Long-tapering to a pointed apex. the sides of the angle somewhat concave. Acute. Sharply angled. the sides of the angle essentially straight. the angle less than 90 degrees. Adaxial. Pertaining to the side of an organ toward the axis. such as the upper surface of a leaf; cf. abaxial. Adnate. Pertaining to the fusion of one structure to another. such as the stipules to the petioles in some species of Potamogeton . Adventitious. Pertaining to organs arising from an irregular or unusual position. such as roots from the stem. or leaves or buds from a root. Aerenchyma. Type of plant tissue consisting of thin-walled cells with numerous. large intercellular spaces. Agamospermy. Pertaining to the development of seeds without fertilization; a type of apomixis. Aggregate. Crowded into a dense cluster. but remaining separate . Alternate. Leaves or other parts borne with but one at each level on the stem. Ament. A catkin; a lax. usually pendulous. spike-like inflorescence . usually bearing apetalous. unisexual flowers. Anastomosing. Pertaining to veins or ridges branching and merging so as to form a network. Androecium. A collective term for the stamens. Androgynous. Pertaining to an inflorescence having both staminate and pistillate flowers. the staminate flowers in the apical . or upper. portion; cf. gynaecandrous. Annual. A plant which completes its life history within one year. Anther. The pollen-bearing part of the stamen. Anthesis. Flowering. or strictly the time of expansion of a flower when pollination may take place; often used to designate the flowering period. Antrorse. Having hairs or processes directed upward or forward ; cf. Retrorse. Apetalous. Without petals. Apex. The tip or distal end. 431 Aphyllous. Lacking leaves. Apical. Pertaining to the apex. Apiculate. Tapering to an abrupt short. pointed tip. Apocarpous. Gynoecium with separate carpels. Apomictic. Typically. setting seed without fertilization. Appressed. Lying close and pressed against; adpressed. Aquatic. Living in water. Arborescent. Approaching the size and habit of a tree. Arcuate. Arching; bowed; moderately curved. Areolate. Marked out into small spaces. Aril. An appendage or outer covering of a seed. growing out from the hilum or funiculus; often appears as a fleshy seed covering. Arillate. Pertaining to a seed having an ari!. Aristate. Bearing a stiff bristle-like awn or seta; tapered to a very narrow. much elongate apex. Armed. Provided with any kind of strong or sharp defense structures such as thorns. spines. prickles. barbs. Articulate. Jointed; proVided with joints or places where separation may naturally take place. Ascending. Rising upward; produced somewhat obliquely or indirectly upward. Attenuate. Gradually narrowed to a point at apex and/or base. Auricle. An ear-shaped part of appendage. such as the projections at the base of some leaves. Auriculate. Having ear-like lobes; having auricles. Awl-shaped. Narrow and sharp-pOinted. gradually tapering from the base to a slender. stiff point; subulate. Awn. A stiff. bristle-like appendage. often at the end of a structure. Axil. The angle between an organ and the axis which bears it. such as between the leaf and the stem. Axillary. Located in the axil. Axis. The main line of development of a plant or organ. such as the main stem. Barbed. Having rigid points or short bristles. usually reflexed. Beaked. Ending in a firm. prolonged slender tip. such as beaks of fruits or pistils; rostrate. Bearded. Bearing long stiff hairs or bristles; pertaining to a tuft or zone of pubescence. Berry. A fleshy fruit with few to many seeds. but lacking stones. Biconvex. Lenticular; having both surfaces rounded. Biennial. A plant which requires two years to complete its life cycle. the first year growing only vegetatively. often producing only a basal rosette. then flowering. fruiting. and dying the second year. 432 Glossary of Plant Terms Bifid. Two-cleft; split into two segments, such as at the apex of some leaves or petals, Bilabiate. Two-lipped. Bilaterally symmetrical. Descriptive of a flower or set of flower parts which can be cut through the center into two equal and similar parts along only one plane; zygomorphic; irregular. Bipinnate. Twice, or...