CONIFERS AND GYMNOSPERMS
Within the plant kingdom there are two major groups of seed-producing plants: angiosperms and gymnosperms. Angiosperms are flowering plants; the seed is usually produced in an ovary (fruit) which develops in the flower. Gymnosperms are trees or shrubs in which the ovules or seeds are naked, growing on the scales of cones or conelike structures (not enclosed in an ovary). Cycads are the most primitive extant gymnosperms.
Conifers are the largest subgroup of gymnosperms, and are further divided into the pine family (Pinaceae), which includes pines, firs, spruces, hemlocks, larches, and Douglas-firs; the cypress family (Cupressaceae), which includes coast redwood and giant sequoia (formerly included in Taxodiaceae); junipers, incense cedar, redcedar, cypresses and false-cypresses; and the yew family (Taxaceae).
Conifers usually, but not always, have needle- or scale-like leaves, and are usually, but not always, evergreen, rather than deciduous. Some are shrubs, but most are trees.
This site includes conifers native to California, and also includes many exotic conifers that are cultivated and thrive in the Mediterranean-type climate of the San Francisco Bay Area, plus a few I found in local botanic gardens and couldn't resist. Descriptions are based on field observations, coursework, and reading. References here.