Displaying 1501 - 1525 out of 1575 Object(s)

Term Definition
Type "A nomenclatural type (typus) is that element to which the name of a taxon is permanently attached, whether as the correct name or as a synonym. The nomenclatural type is not necessarily the most typical or representative element of a taxon." This quotation is from the International Code of Nomenclature for algae, fungi, and plants (Shenzhen Code) 2018. The ICN (or Code) is updated every six years based on proposals approved at the International Botanical Congress which meets at different places in the world. The latest Code is available online here: https://www.iapt-taxon.org/nomen/main.php Type
Type specimen A specimen chosen to represent a species and is cited as such in the publication in which the species is described. There are different types of types, e.g. see holotype, isotype, syntype. The International Code of Nomenclature for algae, fungi, and plants now requires that one specimen be designated as the holotype. Type specimen
Umbel A convex- or flat-topped inflorescence with all pedicels arising from the same point. Umbel
Umbela Una inflorescencia distalmente convexa, cuyos pedicelos salen de un mismo punto de inserción. Las umbelas compuestas son típicas de las Apiaceae y algunas especies de Araliaceae y Smilacaceae Umbela
Umbell A convex- or flat-topped inflorescence with all pedicels arising from the same point. Umbell
Umbo A relatively small protrusion usually in the middle of a structure; e.g., the operculum of a fruit. Umbo
Umbonate Referring to a structure, such as a fruit apex, that possesses an umbo. Umbonate
Unbranched inflorescence An inflorescence with a single rachis. Unbranched inflorescence
Uncinate Hooked at the apex. Uncinate
Uncinate Hooked at the apex, usually refers to stiff trichomes that stick in the fur or clothing of animals to facilitate seed dispersal. Uncinate
Understory tree A tree growing in a hypothetical stratum in the forest consisting of the crowns of trees found below the canopy and usually less than 20–25 meters tall at maturity. Understory tree
Understory tree A species of tree in which adult individuals do not reach the more-or-less continuous canopy tree layer of a forest. Understory tree
Undulation (adj. = undulate) Wavy, usually referring to the margin of a structure such as a leaf. Undulation (adj. = undulate)
Unguiculate Referring to a structure, such as a petal, the is abuptly constricted toward the base (having a claw). Same as clawed. Unguiculate
Uni- A prefix meaning one. Uni-
Unicate collection Referring to a collection number that is represented by a single herbarium specimen. Unicate collections are made when additional collections are not available, when a plant is rare and permission has been obtained to make a collection that does not adversely impact the population from which it is collected, or when a species is so well known that the only reason for collecting it is to document its presence in a specific locality. For more information about plant collecting see Tropical Plant Collecting: From the Field to the Internet. This book can be purchased at: http://tecceditora.com/ or Amazon.com. Unicate collection
Unilaterally winged seed Referring to a seed wing that arise from one side. Unilaterally winged seed
Uniseriate perianth Referring to a perianth with a single whorl composed of either the calyx or the corolla; e.g., the perianth of Nyctaginaceae and Thymelaeaceae. Uniseriate perianth
Unisexual flower Referring to a flower with either functional stamens or functional gynoecia but not both. Same as imperfect flower. Unisexual flower
Unitegmic ovule An ovule with one integument. Unitegmic ovule
Upper septum In neotropical Lecythidaceae, the part of a wall-like partition of a locule located above an articulation (often only seen as a thin line), as seen in longitudinal section, that divides the septum into a lower part and an upper part. Upper septum
Urceolate Shaped like an urn, same as urn-shaped. Urceolate
Urn-shaped Shaped like a vase that is wide at the base and narrower at the apex. Same as urceolate. Urn-shaped
Urticating trichomes Trichomes that cause itching or burning sensations such as in some species of Euphorbiaceae and Urticaceae; sometimes called urticating hairs but urticating trichomes is preferred because it limits the term to plants. Urticating trichomes are thought to protect the plant from predators. Urticating trichomes
Valva Cada uno de los segmentos de un fruto dehiscente que hipotéticamente representa a un carpelo del ovario Valva