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Pubescence (adjective = pubescent)
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Referring to plants with some or all of their parts covered with trichomes. |
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Pulvinate
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Possessing pulvini. |
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Pulvinulus (pl. = pulvinulus, adj. = pulvinate or pulvinulate)
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An enlargement at the base of the petiole or petiolule of leaves. |
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Pulvinus (plural = pulvini)
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An enlargement of a portion of the petiole, without an apparent function (e.g., Protium, Burseraceae) or sometimes controlling the orientation of the leaf or leaflet (e.g., Mimosa polydactyla and M. pudica, Fabaceae). |
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Punctate
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With small dots or streaks that transmit light when held against a light source, with sunken glands, or colored dots; especially easy to see in species of Myrtaceae and Rutaceae. |
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Punctation (adj. = punctate)
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A translucent glandular dot or streak such as found on the leaves of Myrtaceae or Rutaceae or an opaque dot found in other families, such as the Lecythidaceae. |
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Pustule (adj. pustulate)
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A small pimple-like eruption from the surface of part of a plant; e.g., from the hypanthium. |
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Pustule (adj. pustulate)
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A small pimple-like eruption from the surface of part of a plant; e.g., from the hypanthium. |
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Pyrene
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In the Burseraceae, the part of the fruit surrounding a seed or seeds that is derived from the endocarp and is sometimes surrounded by a pseudaril. Similar to a stone but we restrict stones to only drupes or drupelets with a single seed. |
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Pyxidium, pyxidiate
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A capsular fruit with circumscissile dehiscence. |
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Quaternary vein
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Referring to fourth order leaf veins which are intermediate in diameter between tertiary and quinary veins. |
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Raceme
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An indeterminate inflorescence with a single axis, the flowers borne on pedicels of more or less equal length, and the uppermost flower the youngest. Compare with spike. |
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Rachilla
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The axis of a spikelet of a Cyperaceae or a Poaceae along which are placed the florets. |
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Rachis (alt. spelling = rhachis)
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The axis of a compound leaf (excluding the petiole) or of an inflorescence (excluding the peduncle); in legumes, that part of the leaf axis bearing leaflets of any order. |
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Rachlla
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A secondary axis of an inflorescence; e.g., the axis of the spikelet in Poaceae or the axis that bears the flowers in Arecaceae. |
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Radial thickenings
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A series of protuberances arranged in a spoke-like pattern around the top of the supracalycine zone just outside the line of opercular dehiscence. |
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Radially symmetrical flower
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A flower, capable of being divided, by more than one line passing through the middle of the flower, into two equal parts that are mirror images of one another; e.g., in Gustavia (Lecythidaceae), species of Myrtaceae, and species of Rubiaceae. Same as actinomorphic, polysymmetric, and regular flowers and opposite of zygomorphic, monosymmetric, bilateral, and irregular flowers. This term can refer to other plant parts as well. |
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Radiate capitulum (head)
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Inflorescence of Asteraceae with marginal ray flowers and central disk flowers. |
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Radicle
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The lower portion of the embryo that develops into the root. Same as hypocotyl. |
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Rain forest
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A low, large tree dominated forest found from sea level to around 500 meters in Latin America. Dominant trees families are members of the Burseraceae, Chrysobalanceae, Lecythidaceae, Moraceae, Sapotaceae etc. but the composition of the forest can vary geographically, for example, the rain forests of eastern Brazil are sometimes dominated by species of Myrtaceae. The largest trees in neotropical rain forests usually do not exceed 65 meters in height. True rain forest does not have a marked tree season but currently the rain forest concept does include some forests with short dry seasons. |
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Ramet
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An individual part of a clone, e.g., an offshoot. |
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Ramiflorous
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Producing flowers on leafless branches or leafless parts of stems; a special type of cauliflory. Compare with cauliflorous. |
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Ramiflorous inflorescence
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Refers to inflorescences that arise from the branches. Inflorescences that arise from the trunk are called cauliflorous. The branches can be much smaller in diameter than those shown here. |
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Ramiflorous inflorescence
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Refers to inflorescences that arise from the branches. Inflorescences that arise from the trunk are called cauliflorous. The branches can be much smaller in diameter than those shown here. |
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Raphe
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A ridge on a seed formed by the fusion of the funicle to the seed coat, usually indicated by a scar after the seed has been formed. |
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