In lieu of an abstract, here is a brief excerpt of the content:

1 KEY TO THE FAMILIES Note: In the longer keys reference is made, in square brackets, to the number of the couplet from which you last came; page references are not given, since the families are in alphabetic order. Starting pages for major groups are as follows: Ferns and Fern Allies, p. 17 Gymnosperms, p. 38 Angiosperms, p. 42 1a. Plants not producing seeds or true flowers, but reproducing by spores; fern-like, moss-like, rush-like plants. Ferns and Fern Allies 1b. Plants producing seeds, either by means of flowers or cones; plants of various aspects (seed plants) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (2) 2a. Leaves needle-like or scale-like; evergreen trees and shrubs, never with flowers; ovules and seeds on the open face of a scale or bract (rarely the cone becomes a fleshy “berry” in Juniperus and Sabina). Gymnosperms 2b. Leaves various, seldom needle-like or scale-like (if so, flowers are present), rarely evergreen; ovules and seeds borne in a closed cavity (carpel; ovary). Angiosperms, Flowering Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (3) 3a. Parasitic or saprophytic, often highly colored but not green (mistletoe, in this category , has some chlorophyll but is yellowish and epiphytic). Key A 3b. Not parasitic, or at least having green leaves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (4) 4a. Stems thick and succulent, spiny; true leaves absent or greatly reduced and early deciduous. Cactaceae, CaCtus Family 4b. Not as above . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (5) 5a. Leaves all basal, with circular blades covered with stalked, glistening red glands; flowers in a raceme. Droseraceae, sundew Family 5b. Not as above, not insectivorous plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (6) 6a. Submerged plants, with or without floating leaves. Key B 6b. Terrestrial or semiaquatic, not submerged nor with floating leaves . . . . . . . . . . . . (7) 7a. Vines, climbing or twining among other plants, often possessing suckers or tendrils, not merely creeping on the ground. Key C 7b. Herbaceous or woody plants, not vines (the Smilacaceae have tendrils) . . . . . . . . (8) 8a. Leaves usually parallel-veined; flower parts in 3s; stem hollow or with scattered vascular bundles; herbaceous (except Agavaceae and Nolinaceae); seeds with 1 cotyledon (but see also Limnanthaceae, which has floral parts in 3s, otherwise a typical dicot). Key D 8b. Leaves usually netted-veined; flower parts in 5s, 4s, or 2s; stems with vascular bundles arranged in a ring around the pith; herbaceous or woody; seeds usually with 2 cotyledons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .(9) 9a. Trees or shrubs. Key E 9b. Herbaceous, sometimes woody at the very base. Key F KEY A (Parasites/saprophytes) 1a. Attached to the bark of trees, or by suckers to the aerial stems of herbs. . . . . . . . (2) 1b. Without obvious attachments to the aerial parts of their hosts . . . . . . . . . . . . . . . (3) 2a. Attached to the trunks of branches of evergreen trees. Viscaceae, mistletoe Family 2b. Thread-like orange or yellow plants attached by suckers to aerial parts of herbs. Cuscutaceae, dodder Family 2 3a. Flowers actinomorphic, in a spike-like erect or nodding raceme. Monotropaceae, PinesaP Family 3b. Flowers zygomorphic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (4) 4a. Flowers tubular, the petals united; ovary superior. Orobanchaceae, BroomraPe Family 4b. Flowers with separate petals; ovary inferior. Orchidaceae, orChid Family KEY B (Aquatics) 1a. Plants usually not more than 1 cm long, free-floating or submerged, with no attachment whatever . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (2) 1b. Plants not free-floating, or much larger if appearing so. . . . . . . . . . . . . . . . . . . . . . (3) 2a. [1] Plants disk-like or thallus-like, without true stems and leaves, free-floating or submerged. Lemnaceae, duCkweed Family 2b. Plants with obvious leaves arranged in 2 ranks along a short stem, free-floating. Salviniaceae, waterFern Family, in Ferns and Fern Allies 3a. [1] Stems short and lacking, the leaves attached to the bottom, linear-elongate, the tips floating on the surface. Sparganiaceae, Burreed Family 3b. Plants with definite stems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (4) 4a. [3] Leaves simple, entire or slightly toothed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (5) 4b. Leaves distinctly lobed, compound, or finely dissected . . . . . . . . . . . . . . . . . . . . . (17) 5a. [4] Leaves linear or oblong, arranged in whorls . . . . . . . . . . . . . . . . . . . . . . . . . . . . (6) 5b. Leaves variously shaped, not whorled. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (7) 6a. [5] Leaves translucent, lax, 2 cell-layers thick; flowers, if present, sessile (carpellate) or long-pedicelled (staminate). Hydrocharitaceae, FrogBit Family 6b. Leaves opaque, rather rigid unless submerged, more than 2 cell-layers thick; flowers sessile in the leaf axils. Hippuridaceae, mare’s tail Family 7a. [5] Leaves almost orbicular, deeply cordate, very thick and leathery; flowers large, yellow, solitary. Nymphaeaceae, Pondlily Family 7b. Leaves narrower, not cordate; flowers not as above. . . . . . . . . . . . . . . . . . . . . . . . . (8) 8a. [7]Flowersblueoryellow,with6tepalsand3stamens.Pontederiaceae,PiCkerelweed Family 8b. Flowers greenish or colored, but not blue or yellow . . . . . . . . . . . . . . . . . . . . . . . . (9) 9a. [8] Leaves linear or filiform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (10) 9b. Leaves with distinctly broadened blades . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (14) 10a. [9] Flowers in spikes...

Share