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Cetrelia Cetrarioides-1
''Cetrelia'' is a genus of leafy lichens in the large family Parmeliaceae. They are commonly known as sea-storm lichens, alluding to the wavy appearance of their lobes. The name of the genus, circumscribed in 1968 by the husband and wife lichenologists William and Chicita Culberson, alludes to the former placement of these species in the genera '' Cetraria'' and '' Parmelia''. The main characteristics of the genus are the broad, rounded lobes of the greyish-green lichen body, and the presence of tiny pores in the outer surface (the cortex) that enable gas exchange. The lower surface of the lichen is brown to black with few root-like rhizines to act as holdfasts, resulting in a fairly loose attachment to the surface the lichen is on. Sexual reproductive structures are usually not present, so the physical characteristics used to distinguish between ''Cetrelia'' species include the presence or absence of asexual reproductive structures such as isidia, soredia, and lobules ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Willow
Willows, also called sallows and osiers, from the genus ''Salix'', comprise around 400 speciesMabberley, D.J. 1997. The Plant Book, Cambridge University Press #2: Cambridge. of typically deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions. Most species are known as willow, but some narrow-leaved shrub species are called osier, and some broader-leaved species are referred to as sallow (from Old English ''sealh'', related to the Latin word ''salix'', willow). Some willows (particularly arctic and alpine species) are low-growing or creeping shrubs; for example, the dwarf willow (''Salix herbacea'') rarely exceeds in height, though it spreads widely across the ground. Description Willows all have abundant watery bark sap, which is heavily charged with salicylic acid, soft, usually pliant, tough wood, slender branches, and large, fibrous, often stoloniferous roots. The roots are remarkable for their toughness, size, and tenacity to live ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
