There are more than 250,000 known species of plants. A life time of specialization would be needed to know most of them inti­mately. But these many species fall into a few hundred families.

   An earnest student or careful ob­server can acquaint himself with so many of these families that he will recognize the relationships of the majority of the plants he sees, no matter how widely he travels. The family makes the best unit for a thorough general knowledge of plants or animals.

   To secure a clear picture of the plant kingdom it is necessary to begin with the larger groups. The reader will now gather up his equipment of keen eyes, alert mind, and good perseverance and he is ready to start on a most fascin­ating journey through the Kingdom of Plants. 'R you ready? Let's go!

   The plants are usually divided into four great groups. It is commonly recognized that some of these groups are "artificial". The Thallophyta in particular includes many plants which are some­what alike in their simplicity but which are evidently widely disrelated.

   1a) Plants without distinction of root, stem and leaf; without flowers, both aquatic and terrestrial; algae; fungi, and lichens. "HAVE NO ARCHEGONIA". Figs. 1 to 200.
Division THALLOPHYTA p. 10

   1b) Plants with distinct leaves; with or without roots or flowers

   2a) Small plants (to 4 or 5 inches tall) with green or gray-green leaves, or tiny leaf-like forms on damp earth or floating on water. No true roots or flowers. (Some small oval green discs floating on quiet water with roots suspended beneath are flower­ing plants and do not belong here.) "HAVE ARCHEGONIA BUT NO VASCULAR BUNDLES". (Mosses and Liverworts.) Figs. 201 to 253.
Phylun BRYOPHYTA p. 70

   2b) Plants with true roots and vascular bundles; mostly with veiny leaves

   3a) Plants without flowers or seeds, herbs (not woody), propagated by spores. Figs. 254 to 265. "HAVE VASCULAR BUNDLES BUT NO SEEDS". (The Ferns, etc.)
Phylum PTERIOOPHYTA p. 86

   3b) Plants with flowers (sometimes very simple; one tiny stamen or one pistil may constitute a flower) and seeds. "HAVE SEEDS". Figs. 266 to 472. (The seed-bearing plants.)

   1a) Plants green, with chlorophyll, thus organizing their own food by photosynthesis. Figs. 1 to 116.
Subdivision PHYCOPHYTA, The Algae

   1b) Plants without chlorophyll (not green). Living parasitically on living plants or animals or as saprophytes on dead, organic matter. Figs.127 to 200. Subdivision MYCOPHYTA, The Fungi p.47

   1c) Dual organisms in which a green plant species (alga) is held in parasitic embrace by a species of fungus. Usually gray- green or yellow-green but sometimes displaying bright colors. Common on tree trunks, rocks and often growing directly on the ground. Figs. 117 to 126.
The Lichens p. 44