Division Bryophyta (Mosses & Liverworts)

Mosses have minute "leaves" and stalks bearing a terminal capsule (sporangium) containing spores; moss sex organs (male antheridia and female archegonia) are typically produced on the leafy gametophytes of separate male and female plants; liverworts have a dorsi-ventrally flattened thallus with tiny palmlike stalks bearing male and female sex organs; the gametophyte thallus of some species also bears small, cuplike structures called gemmae cups; the cups contain lens-shaped buds called gemmae which can grow asexually into new thallus plants; there are aquatic and terrestrial forms of mosses and liverworts, some of which have a flattened, thallus that superficially resembles certain forms of green algae; these fascinating little nonvascular embryophytes are often subdivided into two separate divisions.

Division Psilophyta (Psilotum)

Primitive leafless vascular plants bearing 3-lobed sporangia on branches; includes the unusual wisk fern (Psilotum nudum; plants such as this (including treelike forms as tall as telephone poles) were abundant in ancient swamplands 300 million years ago.

Division Lycophyta (Club Mosses)

Minute "true" leaves superficially resembling a moss; terminal, stalked spore-bearing strobilus in Lycopodium; in Selaginella male and female sporangia are produced in the leaf axils; also includes the bizarre quillworts (Isoetes); many fossil forms (some tree-like) dating back 300 million years ago; Lycopodium spores used for dust explosion demonstrations, and were used for flash powder prior to flash bulbs and strobe lights.

Division Sphenophyta (Horsetails)

Primitive vascular plant group of the Carboniferous Period (300 million years ago) with jointed stems, whorls of tiny scale-like leaves at the nodes, and a terminal spore cone (strobilus); some species with dense branches at nodes, apparently resembling a bushy horse's tail to some botanists; also called "scouring rushes" because the silica-impregnated stems were used to clean pots and pans; many fossils, including tree-like forms dating back 300 million years ago; the present-day genus Equisetum is a living fossil with several species that are the only living representatives of this ancient group of vascular plants.

Division Pterophyta (Ferns)

Leaves (fronds) with sporangia clusters (sori) on the underside; fronds arising from subterranean, creeping rhizomes and from trunks of tree-like forms (called tree ferns); includes the orders Filicales (true ferns Adiantum, Pteridium, Dryopteris, Polypodium, Polystichum, Pellaea, etc.), Marsileales (clover-leaf ferns Marselia and pillworts Pillularia), Ophioglossales (adder's tongue fern Ophioglossum), and Salviniales (water ferns Azolla and Salvinia). Sometimes these latter "ferns" are called "fern allies" because they belong to different orders; i.e. they do not belong to the order Filicales (the order of true ferns).

An "air fern" (Sertularia argenta). This is NOT a true fern. It is the skeletal remains of a dead marine hydrozoan which has been dyed green. Hydrozoans belong to the animal Phylum Cnidaria (Class Hydrozoa), and include many marine and freshwater species. [True corals and sea anemones belong to the Class Anthozoa and jellyfish belong to the Class Scyphozoa.] Hydrozoans form intricately branched colonies attached to rocks and ocean bottoms. The fernlike branches are composed of numerous, minute, chitinous chambers where the individual animals once lived. When the colony was alive, a tentacle-bearing polyp occupied each chamber (hydrotheca). The "air fern" does not grow because it is dead. In fact, it has no roots or leaves and the green coloring will dissolve if you soak the air fern in water. Most commercial air ferns are collected by trawlers in the North Sea. They are sold as a curiosity or decorative "indoor plant," and as underwater decorations for aquaria.

Note: Although it has jellyfish characteristics, the infamous Portuguese man-of-war (Physelia) actually belongs to the Class Hydrozoa (Order Siphonophora). It is a large colonial animal with a bladderlike float or air sac and long stinging tentacles that hang down in the water. An accidental encounter with one of of these creatures can be a painful and dangerous experience for a swimmer.

Division Cycadophyta (Cycads)

Palm-like plants with large seed and pollen cones; flourished during the days of the dinosaurs and undoubtedly were a major food supply for herbivorous dinosaurs; cycads were so numerous in Mesozoic times that this era is often called the Age of Cycads and Dinosaurs; cycads are dioecious species with pollen cones and seed cones produced on separate male and female individuals; in some species, the enormous pollen and seed cones may reach 3 feet in length and may weigh up to 90 pounds, the largest of all living cone-bearing plants.

Division Ginkgophyta (Maidenhair Tree)

Seeds borne in pairs on dwarf shoots; leaves similar in shape to the maidenhair fern (Adiantum); a true living fossil dating back 185 million years; only one living representative Ginkgo biloba.

Division Gnetophyta (Gnetum & Welwitschia)

A remarkable plant division including Ephedra, Gnetum and Welwitschia; stems of Ephedra are jointed with small scale-like leaves at the nodes; the bizarre, shredded, wind-blown leaves of Welwitschia arise from a woody caudex on the desert floor; this division includes species with vessels and other characteristics typically found in flowering plants.

Division Coniferophyta (Cone-Bearing Trees & Shrubs)

Seeds borne on the surface of woody scales, the overlapping scales forming a cone; includes pine (Pinus), fir (Abies), spruce (Picea), hemlock (Tsuga), larch (Larix), juniper (Juniperus), and cypress (Cupressus); also includes the tallest (redwood) and most massive (giant sequoia) living organisms; some species (especially pines) require fire for seed germination and regeneration.

Division Anthophyta (Flowering Plants)

Class Monocotyledoneae: Monocots. Flower parts in 3's or multiple of
3's; one cotyledon inside seed; parallel leaf venation; includes Lilium,
Amaryllis, Iris, Agave, Yucca, orchids, duckweeds, grasses, & palms.

Class Dicotyledoneae: Dicots. Flower parts in 4's or 5's; 2 cotyledons
inside seed; branched or net leaf venation; includes the most species
of flowering herbs, shrubs and trees.

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