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: Of plant duration, a plant whose life span ends within one year after germination, e.g. a winter annual germinating in the autumn and flowering in the spring (esp. in Mediterranean climates), approximately synonymous to therophyte, c.f. biennial, ephemeral, perennial, c.f. also of flowering with respect to architecture, hapaxanthic, monocarpic, pleonanthic.
Definition: Of life span, a plant which lives for more than one but less than two years after germination, c.f. annual, ephemeral, perennial, of flowering with respect to architecture, hapaxanthic, monocarpic, pleonanthic.
Definition: one of three metabolic pathways for carbon fixation in photosynthesis, along with C4 and CAM. This process converts carbon dioxide and ribulose bisphosphate (RuBP, a 5-carbon sugar) into 3-phosphoglycerate through the following reaction:\r\n\r\nCO2 + H2O + RuBP → (2) 3-phosphoglycerate\r\n\r\nThis reaction occurs in all plants as the first step of the Calvin–Benson cycle.
Definition: A terrestrial plant is a plant that grows on or in or from land. Other types of plants are aquatic (living in water), epiphytic (living on trees) and lithophytic (living in or on rocks)
