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Cycads / ˈ s aɪ k æ d z / are seed plants that typically have a stout and woody 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.
The spermatophytes were traditionally divided into angiosperms, or flowering plants, and gymnosperms, which includes the gnetophytes, cycads, [5] ginkgo, and conifers. Older morphological studies believed in a close relationship between the gnetophytes and the angiosperms, [6] in particular based on vessel elements.
Spermatophytes: Division: † Pteridospermatophyta: Groups included †Calamopityales †Callistophytales †Caytoniales †Gigantopteridales †Glossopteridales †Lyginopteridales †Medullosales †Peltaspermales †Corystospermales (also referred to as Umkomasiales) †Petriellales; Excluded Angiospermae (flowering plants) Cycadales (cycads ...
The gymnosperms (/ ˈ dʒ ɪ m n ə ˌ s p ɜːr m z,-n oʊ-/ ⓘ nə-spurmz, -noh-; lit. ' revealed seeds ') are a group of woody, perennial seed-producing plants, typically lacking the protective outer covering which surrounds the seeds in flowering plants, that include conifers, cycads, Ginkgo, and gnetophytes, forming the clade Gymnospermae [2] The term gymnosperm comes from the ...
The sperm of members from the genus are large, as is typical of cycads, and Z. roezlii is an example; its sperm are approximately 0.4 mm long and can be seen by the unaided eye. [ 11 ] It was long believed that Zamia plants, like all cycads, relied completely on wind pollination .
In ferns and seed plants (including cycads, conifers, flowering plants, etc.) the sporophyte is the dominant generation; the obvious visible plant, whether a small herb or a large tree, is the sporophyte, and the gametophyte is very small. In bryophytes and ferns, the gametophytes are independent, free-living plants, while in seed plants, each ...
Cycas pectinata has the most widespread distribution in South Asia, and is the only South Asian cycad species found outside India and Sri Lanka. India Cycas ...
Cycas beddomei is a species of cycad in the genus Cycas, native to India, where it is confined to a small area of Andhra Pradesh state in the Tirumala Hills in scrubland and brush covered hills. Superficially similar to Cycas revoluta , it has erect, solitary stems.