Cycads / ˈsaɪkædz / are seed plants that typically have a stout and woody (ligneous) trunk with a crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants of a species are either male or female. Cycads vary in size from having trunks only a few centimeters to several meters tall.

The World List of Cycads (WLoC) is a comprehensive reference for cycad taxonomy, nomenclature, biology, and literature. Learn more about us. The WLoC is produced under the auspices of the IUCN/SSC Cycad Specialist Group (CSG) and …

Cycads are gymnosperms distinguished by crowns of large pinnately compound leaves and by cones, which are typically borne at the end of the trunk in the centre of whorled branches. Some cycads have tall unbranched trunks with an armourlike appearance; others have partially buried stems with swollen (tuberous) trunks.

2024年4月1日 · Cycads, the earth's most ancient extant relict plants, represent the primordial group of seed plants (Wang et al., 2021). They offer an invaluable historical lens on growth and evolution, placing them at the heart of studies on the origins and …

Cycads are an ancient group of vascular plants that were once a prominent component of the world’s flora. The oldest cycad fossils date to the early Permian (280 million years ago) or late Carboniferous period (300–325 million years ago).

Cycads are the most primitive of surviving gymnosperms, or cone-bearing plants, with palm-like leaves and a thick soft stem of storage tissue, mostly lacking any true wood. Their fossil record dates back to the early Mesozoic – about 250 million years.

2024年4月1日 · Cycads, deriving from the ten genera of Cycadaceae and Zamiaceae, stand as the most archaic and basic lineage of seed plants, representing an early clade of gymnosperms (Chaw et al., 1997; Christenhusz et al., 2011). Cycas L. is the most widely distributed and is particularly abundant in southwestern China (Zheng et al., 2017). Cycads, also ...

Cycads (order Cycadales) are an ancient group of palmlike gymnosperms with about 300 extant species across three families. The plants are distinguished by crowns of large pinnately compound leaves and by large cones .

2022年4月18日 · Identifying genomic features uniquely shared by cycads and other extant seed plants, but not non-seed-producing plants, may shed light on the origin of key innovations, as well as the early...

Cycads are seed plants whose fossils are first found in the early Permian period. [1] They were very common in the Mesozoic era, the age of the dinosaurs, and are still living, but are now much less common. Only nine genera (about 100 species) of cycads are extant nowadays.