Glossary List - The William & Lynda Steere Herbarium

Displaying 951 - 975 out of 1575 Object(s)

Term	Definition
Ocrea	A structure formed of stipules fused into a sheath and surrounding the stem; i.e., a diagnostic character of the Polygonaceae; in palms, an extension of the leaf sheath beyond the petiole insertion, is a different kind of ligule.
Odd-pinnate leaf	Pinnate with an odd number of leaflets; i.e., without a terminal leaflet. Same as imparipinnate.
Opercular opening	The opening of a dehiscent-fruited species of Lecythidaceae.
Opercular rim	The circular scar that indicates where the operculum was attached to the fruit.
Operculate	Possessing an operculum. Same as lid.
Operculum	The lid of the fruit of species with circumscissilely dehiscent fruits as found in many species of Lecythidaceae; a valvelike opening into the stony endocarp of the fruit of some species (e.g., Humiriaceae); referring to a seed with an opening covered by a lid (e.g., Zingiberaceae) or the membranous cover of the nectary in Passiflora (Passifloraceae).
Operculum (plural = opercula)	Lid-like; the lid of a dehiscent fruit as found in many, but not all, Lecythidaceae.
Opposite	Arising from an axis, such as leaves from a stem, in pairs at the same node. Compare with alternate and whorled.
Opposite leaves	Reffering to leaves that arise from an axis in pairs at the same node. Compare with alternate and whorled.
Opuesta	Se refiere a la disposición de las hojas, cuando están en pares, insertas una a cada lado en un mismo nudo. Comparar con alterna y verticilada
Oral setae	Coarse, bristlelike appendages present at the summit of the leaf sheaths of some grasses.
Orbicular	Referring to a two-dimensional structure with a circular outline.
Orbiculate	A an orbiculate shape is widest at the middle and possesses a length to width ratio of greater than 1.1:1 to less than 1.2:1 Based on Hickey (1973). For more information about leaf morphology and leaf architecture see Ellis et al. (2009).
Ostiole	The opening into the syconium (fig) of Ficus (Moraceae).
Outcrossing	In flowering plants, the production of viable seed by the movement of pollen from one plant to another plant.
Outer bark	Dead tissue surrounding branches, trunks, and roots that includes all tissue from the innermost periderm outward.
Outer bark	All tissue of the trunk and stems produced by the cork cambium, this includes the phelloderm, the cork cambium or phellogen, and the cork or phellum (the dead bark tissue).
Outer bark laminated	The outer bark has distinct lines as seen without magnfication. This feature is seen only by making a slash of the bark.
Outer bark smooth	Bark without fissures, scallops, or roughness.
Outer bark thick	The outer bark is markedly thicker than the inner bark.
Outer bark thin	The outer bark is thinner than the inner bark.
Ovary	The part of the gynoecium (=pistil) containing the ovules.
Ovary	The part of the gynoecium containing the ovules.
Ovary cross-section	A section through the ovary made at a right angle to the long or vertical axis of a flower. A term used in the Lecythidaceae to determine the number of locules and to describe the placention of species and genera.
Ovary half-inferior	An ovary of Lecythidaceae that bulges upward at the summit making the ovary appear half-inferior in contrast to an inferior ovary which is truncate at the apex..