Article
Article
Pinopsida
Article By:
Zanoni, Thomas A. Jardín Botánico Nacional, Santo Domingo, Dominican Republic; New York Botanical Garden, New York, New York.
Last reviewed:January 2021
DOI:https://doi.org/10.1036/1097-8542.518600
The single class of the division Pinophyta (Gymnospermae). The class Pinopsida contains both living and fossil taxa. The living representatives of the Pinopsida are woody plants; most are trees with a central axis and excurrent branches. Leaves are simple, alternate, opposite or in whorls, scalelike or needlelike, or rarely planar. The wood lacks vessels and usually has resin canals. Male reproductive structures are aggregated on microsporophylls directly attached to the cone axis. The ovules are borne in compound cones, or they are single or paired at the end of a stalk. The main seed plane is tangential to the cone axis (if the seed scale is regarded as a modified dwarf shoot). The embryo has two or more cotyledons. See also: Pinales; Pinophyta; Plant kingdom; Tree
The content above is only an excerpt.
About AccessScience
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Contributors include more than 10,000 highly qualified scientists and 46 Nobel Prize winners.
MORE THAN 8700 articles covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 19,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information
