Cacti of the Southwest

Glossary

G L O S S A R Y The terms below are defined as they are used in this work to refer to the cacti described, and the definitions are not intended to be so broad as to cover their usage for all other plant groups. Anther. The enlarged, pollen-bearing sac at the tip of a stamen. Apex. The tip or summit of any structure. Apical. Referring to the apex. Areole. A spot in the form of a pit or a raised area marking an opening through the epidermis from which leaves, spines, or other structures grow. Ascending. Not standing perfectly upright, but growing upward. Axil. The angle between a leaf, branch, tubercle, or other outgrowth and the stem. Basal. At or referring to the base or lower part of any structure. Berry. A pulpy or fleshy fruit with numerous seeds embedded in the flesh. Bud. An unopened flower; a growing tip surrounded by its immature perianth segments or leaves. Caespitose. Forming a cluster or clump of stems by repeated branching of the stem at or near the base. Calyx. The outer series of perianth segments, whenever these are dis­ tinct from the inner series. Central. Positioned at or near the center of an area, as opposed to being peripheral in position. A spine originating in the center of the areole as opposed to those growing around the edge of the areole. Character. A characteristic or feature unique enough to have value in distinguishing forms and setting up relationships. Cholla. Any cylindrical-stemmed member of the genus Opuntia. Cilium (pl.: cilia). Very fine, hairlike filaments sometimes forming fringes on the margins of perianth segments. Clone. A local population usually propagated from one individual by vegetative means and therefore uniform genetically and in appearance . Confluent. Running together or more or less coalescing. Corolla. The inner series of perianth segments, when these are distinct from the outer ones; the petals collectively. Decumbent. Lying prostrate on the ground with the tip turning up­ ward. Deflexed. Curved or bent back, down upon itself, or toward the sur­ face of the plant. Recurved. Dehiscent. Splitting open at maturity. Dimorphic. Having two forms. Distal. Situated opposite the point of attachment or origin. Divergent. Spreading apart so as to form opposites. Ecotype. A population which is recognizable by distinct morphologi­ cal and physiological features and which is the result of, but kept separate from its near relatives by environmental barriers; an eco­ logical “race.” Entire.Havingthemargincontinuousandnottoothed,lobed,indented or interrupted. Epidermis. The outer layer of cells on a plant, forming a protective covering. In ordinary usage thought of as including the waxy nonliving layer that overlies the living cells. Erose. Ragged, with irregular indentations, as though bits were ran­ domly chewed away. Felt. A very thick covering of hairs, filaments, or fibers. Fibrous roots. Finely subdivided roots with no obvious thickening or enlarged central root beyond the base of the plant. Filament. The stalk of a stamen; the threadlike part of the stamen that supports the anther. Genotype. A group of organisms having a common genetic makeup. Genus. A grouping of species possessing common characters unique enough to be treated as a unit distinct from others. Glabrous. Smooth and shiny; not pubescent, rough, or hairy. Gland. A secreting structure, usually in the form of a protuberance or appendage, but sometimes a surface. Glaucescence. A thin layer of whitish substance, often called the “bloom” and usually made up of tiny particles of wax, which rub off. 242 cacti of the southwest Globose. Spherical or spheroidal in shape. Glochid. A sharp, hairlike or bristlelike outgrowth equipped with minute and usually invisible barbs so that it resists withdrawal from any tissue. Hilum. The scar on the seed that marks the point at which the seed was attached during growth. Inferior. Beneath or below; in the flower, descriptive of having the ovary appearing below such flower appendages as the perianth and stamens. Intergrade. Not separated by any division into sets, but merging by having an unbroken series of intermediate forms. Lanceolate. Lance-shaped; much longer than broad, widest just above the base, with a gradual taper from there to the tip. Lateral. Growing or positioned at the sides. Linear. Long and narrow, with sides parallel or nearly so, as a blade of grass. Meristem. A body of tissue with the power to divide and differen­ tiate. Microgenus. A nonofficial term used here for genera that have been officiallydescribed,butseemdistinguishedbylessobviousorsignif­ icant characters than the major genera. Midrib. The main or center...