|
Annual Vs. Perennial Plant Evolution
Annual plant, Annuality (living and reproducing in a single year) and Perennial plant, perenniality (living more than two years) represent major Life history theory, life history strategies within plant lineages. These traits can shift from one to another over both macroevolutionary and microevolutionary timescales. While perenniality and annuality are often described as discrete either-or traits, they often occur in a continuous spectrum. The complex history of switches between annual and perennial habit involve both natural and artificial causes, and studies of this fluctuation have importance to sustainable agriculture. (Note that "perennial" here refers to both woody plant, woody and herbaceous plant, herbaceous perennial species.) Globally, only 6% of all plant species and 15% of herbaceous plants (excluding trees and shrubs) are annuals. The annual life cycle has independently emerged in over 120 different plant families throughout the entire angiosperm phylogeny. The life-his ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silphium Head
Silphium (also known as ''silphion'', ''laserwort'', or ''laser'') is an unidentified plant that was used in classical antiquity as a seasoning, perfume, aphrodisiac, and medicine. It also was used as a contraceptive by ancient Ancient Greece, Greeks and Ancient Rome, Romans. It was the essential item of trade from the ancient North African city of Cyrene, Libya, Cyrene, and was so critical to the Cyrenian economy that most of their coins bore a picture of the plant. The valuable product was the plant's resin (''laser'', ''laserpicium'', or ''lasarpicium''). Silphium was an important species in classical antiquity, as evidenced by the Ancient Egypt, Egyptians and Knossos Minoan civilization, Minoans developing a specific glyph to represent the silphium plant. It was used widely by most ancient Mediterranean cultures; the Romans, who mentioned the plant in poems or songs, considered it "worth its weight in denarius, denarii" (silver coins), or even gold. Legend said that it was a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
