Monographs Details: Pinus
Authority: Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Description:Genus Description - Male cones in fascicles at the base of the current year’s growth; female cones woody, maturing at the end of the second or third season and often long-persistent; apophysis (exposed portion of the mature cone-scale) marked by a transverse line or ridge interrupted in the center by a linear to round or quadrate, often elevated or spine-bearing umbo, or the umbo sometimes terminal; evergreen trees or shrubs with dimorphic branches and lvs, the long branches (except in seedlings) bearing only scale-lvs, from the axils of which early appear very short dwarf branches, each bearing a cluster of (1)2–5 needle-like lvs, the cluster surrounded at the base by a bundle- sheath of 1 or more membranous scale-lvs; dwarf branches eventually (after 2–several years) deciduous with the lvs; evergreen trees or shrubs; 2n=24. Nearly 100, N. Hemisphere.