Definition: There is no evidence that the organism produces compounds (allelochemicals) that influence the growth, survival, and reproduction of other organisms.
Definition: A porosity quality inhering in a bearer by virtue of the bearer's being incapable of admitting the passage of gas or liquid through pores or interstices.
Definition: A porosity quality inhering in a bearer by virtue of the bearer's being capable of admitting the passage of gas or liquid through pores or interstices. (or, as in fungi, solids such as spores may be admitted through pores in the hymenium, for example)
Definition: Gravel is an environmental material which is composed of pieces of rock that are at least two millimeters (2mm) in its largest dimension and no more than 75 millimeters.
Definition: An elevated area of land with a flat top and sides that are usually steep cliffs. Mesas form in areas where horizontally layered rocks are uplifted by tectonic activity.
Definition: An area of land of low topographic relief that historically supported grasses and herbs, with few trees, and having generally a mesic (moderate or temperate) climate. Dominated by tall grasses (contrast steppe).
Definition: A color hue with medium-low wavelength of that portion of the visible spectrum lying between yellow and blue, evoked in the human observer by radiant energy with wavelengths of approximately 490 to 570 nanometers.
Definition: Of plant duration, a plant whose life span extends over more than two growing seasons, c.f. annual, biennial, ephemeral, of flowering with respect to architecture, hapaxanthic, monocarpic, pleonanthic
Definition: National Museum of Natural History, Smithsonian Institution (USNM), Washington, District of Columbia, USA.\r\nNMNH and USNM both refer to the National Museum of Natural History. Collections are associated with one or the other acronym. US, the US National Herbarium, is a collection within the National Museum of Natural History. URL for main institutional website, http://www.mnh.si.edu/rc/\r\nURL for institutional specimen catalog, http://collections.mnh.si.edu/
