As the Quaternary Period includes the present, any plant alive today has lived in the period, from lettuce to redwoods to seaweed. The Quaternary Period began roughly 2.5 million years ago and is divided into the Pleistocene and Holocene epochs, with the division occurring a little less than 12,000 years ago.
As the period covers 2.5 million years, various types of plant life existed that went extinct before the present. Examples of plants alive in the Pleistocene epoch but no longer in existence include the orchids Banksia kingii and Banksia strahanensis. Examples of plant extinctions during the Holocene epoch include the Saint Helena olive, the Havana fragrant tree, the Sri Lanka legume tree and the cry pansy. Each of these plants died out in the 19th or 20th centuries.
Unlike some earlier periods of history, the dominant plant life in the Quaternary Period has been flowering plants, which include a majority of easily recognizable plants from apple trees to larches to roses. Non-flowering plants of the period include ferns and mosses.
Climate changes over the 2.5 million years, such as the ice age at the end of the Pleistocene and beginning of the Holocene, modified plant life and ranges throughout the period.