Only vascular plants are treated in the eFlora. Vascular plants are a monophyletic group or clade that includes (1) Lycophytes (often superficially moss-like but with thicker scale-like leaves and axillary sporangia that are often borne in cones), (2) Ferns (most with sporangia borne on abaxial leaf surfaces, a few with sporangia on modified leaf segments or in hard sporangium cases), and Equisetum, with whorled scale leaves and sporangia grouped in terminal cones, (3) Gymnosperms (with seeds generally produced in cones of various forms), and (4) flowering plants (with seeds developing in ovaries of flowers). Flowering plants in California include five clades: Nymphaeales (aquatic, rhizomed; cotyledons 2; some or all leaf blades floating; flower 1, bisexual, parts spirally arranged or in 3s; pollen aperture 1), Magnoliids (terrestrial, often scented from ethereal oils; cotyledons 2; flower parts generally spirally arranged or in 3s; pollen aperture), Ceratophyllales (Ceratophyllum), Eudicots (cotyledons 2; flower parts generally in 4s or 5s; pollen apertures 3+), and Monocots (cotyledon 1; leaf veins generally parallel from base or midrib; flower parts generally in 3s; pollen aperture 1). Unlike all other organisms, vascular plants have true roots, stems, and leaves, with water- and nutrient-conducting (vascular) tissues that also provide structural support.