dd. Upper margin of leaf-scars not concave, but straight

across or projecting upward. _F. pennsylvanica lanceolata_, p. 217.

+OLEACEAE+

+White Ash+

_Fraxinus americana L._

HABIT.--A large tree 50-75 feet high, with a trunk diameter of 2-3 feet; forming an open, pyramidal crown of long, slender, lateral branches and a stout, rather sparse spray.

LEAVES.--Opposite, pinnately compound, 8-12 inches long. Leaflets usually 7-9, 3-5 inches long, 1-2 inches broad; short-stalked; ovate to oblong-lanceolate; entire or obscurely serrate; thick and firm; glabrous, dark green above, paler beneath. Petioles glabrous, stout, grooved.

FLOWERS.--May, before the leaves; dioecious; borne in loose panicles on shoots of the previous season; calyx campanulate, 4-lobed; corolla 0; stamens 2, rarely 3; ovary 2-celled.

FRUIT.--August-September, persistent on the branches until mid-winter or the following spring; samaras 1-2 inches long, in crowded, drooping, paniculate clusters 6-8 inches long.

WINTER-BUDS.--Short, rather obtuse; bud-scales apiculate, keeled, 4 pairs, rusty-brown.

BARK.--Twigs at first dark green, becoming gray or light brown, often covered with a glaucous bloom; gray, deeply furrowed into firm, narrow, flattened ridges on the trunk.

WOOD.--Heavy, hard, strong, close-grained, tough, brown, with thick, lighter colored sapwood.

DISTRIBUTION.--Of common occurrence throughout the state.

HABITAT.--Prefers a rich, moist, loamy soil, but grows in any well-drained situation; common along stream-beds.

NOTES.--Grows rapidly. Easily transplanted. Fairly free from disease. Leaves appear late in spring.

+OLEACEAE+

+Red Ash+

_Fraxinus pennsylvanica Marsh._ [_Fraxinus pubescens Lam._]

HABIT.--A medium-sized tree 30-50 feet high, with a trunk diameter of 1-2 feet; stout, upright branches and slender branchlets form a compact, broad, irregular crown.

LEAVES.--Opposite, pinnately compound, 10-12 inches long. Leaflets 7-9, 3-5 inches long, 1-1-1/2 inches broad; short-stalked; oblong-lanceolate to ovate; slightly serrate or entire; thin and firm; glabrous, yellow-green above, pale and silky-downy beneath. Petioles stout, pubescent.

FLOWERS.--May, with the leaves; dioecious; borne in compact, downy panicles on shoots of the previous season; calyx cup-shaped, 4-toothed; corolla 0; stamens 2, rarely 3; ovary 2-celled.

FRUIT.--Early autumn, persistent on the branches throughout the winter; samaras 1-2 inches long, in open, paniculate clusters.

WINTER-BUDS.--Small, rounded; bud-scales rounded on the back, 3 pairs, rusty-brown, tomentose.

BARK.--Twigs pale-pubescent at first, lasting 2-3 years or often disappearing during the first summer, finally ashy gray or brownish and often covered with a glaucous bloom; brown or dark gray on the trunk, with many longitudinal, shallow furrows; somewhat scaly.

WOOD.--Heavy, hard, strong, brittle, coarse-grained, light brown, with thick, yellow-streaked sapwood.

DISTRIBUTION.--Not a common tree. Most frequent in the southern half of the Lower Peninsula, but has been reported further north, i.e., Drummond's Island and Keweenaw County, Upper Peninsula.

HABITAT.--Prefers wet or moist, rich loam; river-banks; swampy lowlands.

NOTES.--A rapid grower in youth. Fairly immune from insect and fungous diseases.

+OLEACEAE+

+Green Ash+

_Fraxinus pennsylvanica lanceolata (Borkh.) Sarg._ [_Fraxinus lanceolata Borkh._] [_Fraxinus viridis Michx. f._]

Considered by some authors to be a distinct species, and by others a variety of _F. pennsylvanica Marsh._, which it resembles. The main points of difference are:

The usual absence of pubescence from the branchlets, the underside of the leaflets, and the petioles.

The rather narrower, shorter, and more sharply serrate leaflets.

The color of the leaves, which is bright green on both sides.

A very hardy tree, of rapid growth and desirable habit, making it useful for ornamental and street planting. Easily transplanted.

Of rare occurrence in Michigan, but has been reported from several localities.

+OLEACEAE+

+Blue Ash+

_Fraxinus quadrangulata Michx._

HABIT.--A large tree 50-80 feet high, with a trunk diameter of 1-3 feet; small, spreading branches and stout, 4-angled, more or less 4-winged branchlets form a narrow crown.

LEAVES.--Opposite, pinnately compound, 8-12 inches long. Leaflets 5-9, usually 7, 3-5 inches long, 1-2 inches broad; short-stalked; ovate-oblong to lanceolate, long-pointed; coarsely serrate; thick and firm; yellow-green above, paler beneath, glabrous. Petioles slender, glabrous.

FLOWERS.--April, before the leaves; perfect; borne in loose panicles on shoots of the previous season; calyx reduced to a ring; corolla 0; stamens 2; ovary 2-celled.

FRUIT.--September-October, falling soon after; samaras 1-2 inches long, in long, loose, paniculate clusters.

WINTER-BUDS.--Short, rather obtuse; bud-scales rounded on the back, 3 pairs, dark red-brown, somewhat pubescent.

BARK.--Twigs orange, rusty-pubescent, becoming brownish or grayish; on the trunk light gray tinged with red, irregularly divided into large, plate-like scales, often with the shaggy appearance of a Shagbark Hickory.

WOOD.--Heavy, hard, close-grained, brittle, light yellow-streaked with brown, with thick, light yellow sapwood.

DISTRIBUTION.--Occasionally in the southern half of the Lower Peninsula. Nowhere abundant.

HABITAT.--Prefers rich, limestone hills, but grows well in fertile bottom-lands.

NOTES.--Hardy and grows rapidly. A blue dye is made by macerating the inner bark in water.

+OLEACEAE+

+Black Ash+

_Fraxinus nigra Marsh._ [_Fraxinus sambucifolia Lam._]

HABIT.--A tall tree 60-80 feet high, with a trunk diameter of 1-2 feet; slender, upright branches form in the forest a narrow crown, in the open a rounded, ovoid crown.

LEAVES.--Opposite, pinnately compound, 12-16 inches long. Leaflets 7-11, 3-5 inches long, 1-2 inches broad; sessile, except the terminal; oblong to oblong-lanceolate, long-pointed; remotely, but sharply serrate; thin and firm; dark green above, paler beneath, glabrous. Petioles stout, grooved, glabrous.

FLOWERS.--May, before the leaves; polygamo-dioecious; borne in loose panicles on shoots of the preceeding season; calyx 0; corolla 0; stamens 2; ovary 2-celled.

FRUIT.--August-September, falling early, or sometimes hanging on the tree until the following spring; samaras 1-1-1/2 inches long, in open, paniculate clusters 8-10 inches long.

WINTER-BUDS.--Ovoid, pointed; bud-scales rounded on the back, 3 pairs, almost black.

BARK.--Twigs at first dark green, becoming ashy gray or orange, finally dark gray and warted; thin, soft ash-gray and scaly on the trunk. Bark flakes off on rubbing with the hand.

WOOD.--Heavy, tough, coarse-grained, weak, rather soft, dark brown, with thin, lighter colored sapwood.

DISTRIBUTION.--Common throughout most portions of Michigan.

HABITAT.--Prefers deep, cold swamps and low river-banks, but grows in any good soil.

NOTES.--Hardy throughout the state. Not easily transplanted. Foliage falls early in autumn.

+SUMMER KEY TO THE SPECIES OF CATALPA+

a. Leaves 5-8 inches long, thick; flowers 1-1/2 inches across, prominently yellow-spotted; seeds with _pointed_, fringed wings at each end; branches rather crooked and straggling; bark thin, separating into thin scales on the trunk. _C. bignonioides_, p. 227.

aa. Leaves 8-12 inches long, thin; flowers 2-1/2 inches across, not prominently spotted; seeds with _rounded_, wide-fringed wings at each end; branches not crooked and straggling; bark thick, separating into thick scales on the trunk. _C. speciosa_, p. 225.

+WINTER KEY TO THE SPECIES OF CATALPA+

a. Fruiting capsules about 1/4 inch thick; seeds with _pointed_, fringed wings at each end; branches rather crooked and straggling; bark thin, separating into thin scales on the trunk. _C. bignonioides_, p. 227.

aa. Fruiting capsules about 1/2 inch thick, seeds with _rounded_, wide-fringed wings at each end; branches not crooked and straggling; bark thick, separating into thick scales on the trunk. _C. speciosa_, p. 225.

+BIGNONIACEAE+

+Hardy Catalpa+

_Catalpa speciosa Warder._

HABIT.--A tree 50-75 feet high, with a short, often crooked trunk and a broad, rounded crown of slender, spreading branches and thick branchlets.

LEAVES.--Opposite or whorled, simple, 8-12 inches long, 6-8 inches broad; heart-shaped; entire or sometimes slightly lobed; thick and firm; glabrous, dark green above, downy beneath, with clusters of dark, nectariferous glands in the axils of the primary veins, turning black and falling with the first severe frost; petioles long, stout, terete.

FLOWERS.--June-July, after the leaves are full grown; perfect; borne on slender, purplish pedicels in open, few-flowered panicles 5-6 inches long; calyx 2-lobed, purple; corolla white with inconspicuous yellow spots, campanulate, 5-lobed, 2-1/2 inches broad; stamens 2, staminodia 3; ovary 2-celled.

FRUIT.--Ripens in early autumn; slender, 2-celled, cylindrical capsule 10-20 inches long and about 1/2 inch thick; hangs on tree all winter, opening in spring before falling; seeds light brown, 1 inch long, with rounded, wide-fringed wings at each end.

WINTER-BUDS.--Terminal bud absent; lateral buds brownish, globose, inconspicuous.

BARK.--Twigs greenish, often with purple tinge, becoming orange or red-brown and covered with a slight bloom the first winter, finally darker with age; thick, red-brown, broken into thick scales on the trunk.

WOOD.--Light, soft, weak, coarse-grained, light brown, with very thin, almost white sapwood; very durable in contact with the soil.

NOTES.--A native of Illinois, Indiana, and the states adjoining on the south, but much planted in Michigan as a shade and ornamental tree. Closely resembles _C. bignonioides_, but is a larger and hardier tree.

+BIGNONIACEAE+

+Catalpa+

_Catalpa bignonioides Walt._ [_Catalpa catalpa (L.) Karst._]

HABIT.--A tree 40-30 feet high, with a short, thick trunk and a broad, irregular crown of long, crooked branches and coarse, upright branchlets.

LEAVES.--Opposite or whorled, simple, 5-8 inches long, 4-5 inches broad; heart-shaped; entire or sometimes slightly lobed; thin and firm; glabrous, light green above, downy beneath, with dark, nectariferous glands in the axils of the primary veins, turning black and falling with the first severe frost; petioles long, stout, terete.

FLOWERS.--June-July, after the leaves are full grown; perfect; borne on slender, hairy pedicels in compact, many-flowered panicles 8-10 inches long; calyx 2-lobed, green or purple; corolla white with yellow spots, campanulate, 5-lobed, 1-1/2 inches broad; stamens 2, staminodia 3; ovary 2-celled.

FRUIT.--Ripens in early autumn; slender, 2-celled, cylindrical capsule 8-20 inches long and about 1/4 inch thick; hangs on tree all winter, opening in spring before falling; seeds silvery gray, 1 inch long, with pointed, fringed wings at each end.

WINTER-BUDS.--Terminal bud absent; lateral buds, brownish, globose, inconspicuous.

BARK.--Twigs greenish purple, becoming red-brown and marked by a network of thin, flat ridges; thin, red-brown on the trunk, separating into large, thin, irregular scales.

WOOD.--Light, soft, weak, coarse-grained, light brown, with very thin, whitish sapwood; very durable in contact with the soil.

NOTES.--A native of the Lower Mississippi River Basin, but naturalized in southern Michigan, where it is a popular shade and ornamental tree. Foliage appears very tardily in spring.

+CAPRIFOLIACEAE+

+Sheepberry. Nannyberry+

_Viburnum lentago L._

HABIT.--A low tree or shrub 15-25 feet high, with a short trunk 6-10 inches in diameter; numerous tortuous branches form a wide, compact, rounded crown.

LEAVES.--Opposite, simple, 2-4 inches long, one-half as broad; ovate to suborbicular; finely and sharply serrate; thick and firm; lustrous, bright green above, pale and marked with tiny black dots beneath; petioles broad, grooved, more or less winged, about 1 inch long.

FLOWERS.--May-June, after the leaves; perfect; small; cream-white, borne in stout-branched, scurfy, flat, terminal cymes 3-5 inches across; calyx tubular, 5-toothed; corolla 5-lobed, cream color or white, 1/4 inch across; stamens 5, with yellow anthers; ovary 1-celled, with short, thick, green style and broad stigma.

FRUIT.--September; a fleshy drupe, 1/2 inch long, ovoid, flattened, blue-black, borne in few-fruited, red-stemmed clusters; stone oval, flat, rough; flesh sweet, edible.

WINTER-BUDS.--Leaf-buds narrow, acute, red, scurfy-pubescent, 1/2 inch long; flower-buds swollen at the base, with spire-like apex, grayish with scurfy pubescence, 3/4 inch long.

BARK.--Twigs at first light green, rusty-pubescent, becoming dark red-brown; red-brown on old trunks and broken into small, thick plates.

WOOD.--Heavy, hard, close-grained, ill-smelling, dark orange-brown, with thin, whitish sapwood.

DISTRIBUTION.--Frequent throughout the state.

HABITAT.--Prefers rich, moist soil along the borders of forests; roadsides; river-banks.

NOTES.--Too small for street use. Propagated from seed or by cuttings.

FOOTNOTES:

[Footnote A: See page xviii.]

[Footnote B: See page xviii.]

[Footnote C: Although formerly classed under PINACEAE, recent investigations show it to be the type of a distinct family.]

[Footnote D: It is not intended that this key shall serve as a means of identification of any species of _Salix_ found in Michigan, but it has added simply to give a ready comparison of the four species which are described.]

[Footnote E: It is difficult to distinguish between these species in the absence of summer characters. If leaves can be found on or beneath a tree which is sufficiently segregated from similar trees as to avoid any chance for error, the summer key on the opposite page may be used.]

[Footnote F: A discussion has recently arisen as to whether _Betula lenta_ actually exists in the state, some botanists preferring the name _B. alleghanensis Britt._ for the tree we have so long called Black Birch. Pending further investigation the authors have thought best to retain the old name.

Ref.--Britton: North American Trees, pp. 257-8.]

[Footnote G: [1] means that the acorns mature in the autumn of the first season, hence mature acorns will not be found on the tree, but on the ground beneath the tree.

[2] means that the acorns mature in the autumn of the second season, hence immature acorns will be found on the last season's twigs, and mature acorns on the ground beneath the tree.]

+GLOSSARY+

_With page references to explanatory figures._

_Abortion._ Imperfect development or non-development of an organ or part.

_Acuminate._ Gradually tapering to the apex. Page XII.

_Acute._ Terminating with a sharp angle. Page XII.

_Alternate._ Said of leaves, branches, buds, etc., scattered singly along the stem; not opposite.

_Androgynous._ Composed of both staminate and pistillate flowers.

_Anterior._ The front side of a flower, remote from the axis of inflorescence.

_Anther._ The part of a stamen which bears the pollen. Page xiii.

_Apetalous._ Without petals.

_Apex._ The top, as the tip of a bud or the end of a leaf which is opposite the petiole.

_Apiculate._ Ending in a short-pointed tip.

_Appressed._ Lying close and flat against.

_Aromatic._ Fragrant; with an agreeable odor.

_Axil._ The upper one of the two angles formed by the juncture of a leaf with a stem.

_Axillary._ Situated in an axil.

_Bark._ The outer covering of a trunk or branch.

_Bearded._ Bearing a long, bristle-like appendage, or furnished with long or stiff hairs.

_Berry._ A fruit which is fleshy throughout.

_Bi-pinnate._ Twice pinnate.

_Blade._ The expanded portion of a leaf, etc.

_Bloom._ A powdery or waxy substance easily rubbed off.

_Bract._ A more or less modified leaf subtending a flower or belonging to an inflorescence.

_Branch._ A secondary division of a trunk.

_Branchlet._ A small branch.

_Bud._ An undeveloped stem or branch, with or without scales.

_Bud-scales._ Modified leaves covering a bud.

_Bundle-scars._ Dots on the surface of a leaf-scar, which are scars left by the fibro-vascular bundles which run through the petiole into the blade of the leaf. Page XVI.

_Bur._ A spiny fruit.

_Calyx._ The outer part of a perianth, usually green in color. Page xiii.

_Campanulate._ Bell-shaped.

_Capsule._ A dry fruit of more than one carpel which splits at maturity to release the seeds.

_Carpel._ A simple pistil, or one member of a compound pistil.

_Catkin._ A spike of unisexual flowers, each subtended by a bract, and usually deciduous in one piece.

_Chambered._ Said of pith which is interrupted by hollow spaces.

_Ciliate._ Fringed with hairs on the margin.

_Cinereous._ Ash-gray color.

_Claw._ The narrow, stalk-like base of a petal, sepal, etc.

_Cleft._ Cut about half-way to the middle.

_Cluster._ A group of two or more organs (flowers, fruit, etc.) on a plant at a node or end of a stem.

_Compound._ Composed of two or more similar parts united into a whole. _Compound leaf_, one divided into separate leaflets.

_Cone._ A fruit with woody, overlapping scales.

_Conical._ Cone-shaped, largest at the base and tapering to the apex.

_Connective._ The portion of a stamen which connects the two cells of the anther.

_Cordate._ Heart-shaped. Page XII.

_Coriaceous._ Leather-like in texture.

_Corky._ Made of, or like cork.

_Corolla._ The inner part of a perianth, usually bright colored. Page XIII.

_Corymb._ A flower-cluster in which the axis is shortened and the pedicels of the lower flowers lengthened, forming a flat-topped inflorescence, the marginal flowers blooming first. Page XIV.

_Corymbose._ Arranged in corymbs.

_Crenate._ Dentate, with the teeth much rounded. Page XIII.

_Crenulate._ Finely crenate.

_Crown._ The upper part of a tree, including the living branches with their foliage.

_Cutting._ A piece of the stem, root or leaf which, if cut off and placed in contact with the soil, will form new roots and buds, reproducing the parent plant.

_Cyme._ A broad and flattish inflorescence, the central flowers of which bloom first. Page XIV.

_Cymose._ Arranged in cymes.

_Deciduous._ Not persistent; falling away, as the leaves of a tree in autumn.

_Decurrent._ Said of a leaf which extends down the stem below the point of fastening.

_Decussate._ Alternating in pairs at right angles.

_Dehiscent._ Opening by valves or slits.

_Deltoid._ Delta-shaped.

_Dentate._ Toothed, with the teeth usually pointed and directed outward. Page XIII.

_Depressed._ Somewhat flattened from above.

_Dichotomous._ Branching regularly in pairs.

_Digitate._ Said of a compound leaf in which the leaflets are borne at the apex of the petiole; finger-shaped.

_Dioecious._ Unisexual, with staminate and pistillate flowers on different individuals.

_Distribution._ The geographical extent and limits of a species.

_Divergent._ Said of buds, cones, etc., which point away from the twig, or of pine needles, etc., which spread apart.

_Dorsal._ Pertaining to the back or outer surface of an organ.

_Downy._ Covered with fine hairs.

_Drupe._ A fleshy or pulpy fruit in which the inner portion is hard or stony.

_Ellipsoid._ An elliptical solid.

_Elliptical._ Oval or oblong with regularly rounded ends. Page XII.

_Emarginate._ Notched at the apex. Page XII.

_Entire._ Without divisions, lobes or teeth.

_Excrescences._ Warty outgrowths or protuberances.

_Exfoliate._ To cleave off, as of the outer layers of bark.

_Falcate._ Scythe-shaped.

_Fascicle._ A compact cluster of leaves or flowers.

_Fascicled._ Arranged in fascicles.

_Fastigiate._ Said of branches which are erect and near together.

_Feather-veined._ Having veins extending from the midrib to the margin, feather-wise.

_Fertile._ Capable of bearing fruit.

_Fertilization._ The mingling of the contents of a male (pollen) and female (ovule) cell.

_Filament._ The part of a stamen which bears the anther. Page XIII.

_Filamentose_ or _Filamentous_. Composed of threads or filaments.

_Flaky._ With loose scales easily rubbed off (bark).

_Fleshy._ Succulent; juicy.

_Flower._ An axis bearing stamens or pistils or both (calyx and corolla usually accompany these).

_Fluted._ With rounded ridges.

_Fruit._ The part of a plant which bears the seed.

_Germinate._ To sprout, as of a seed.

_Gibbous._ Swollen on one side.

_Glabrous._ Neither rough, pubescent, nor hairy; smooth.

_Gland._ Secreting surface or structure; a protuberance having the appearance of such an organ.

_Glandular._ Bearing glands.

_Glaucous._ Covered or whitened with a bloom.

_Globose._ Spherical or nearly so.

_Globular._ Nearly globose.

_Gregarious._ Growing in groups or colonies.

_Habit._ The general appearance of a plant, best seen from a distance.

_Habitat._ The place where a plant naturally grows, as in water, clay soil, marsh, etc.

_Hairy._ With long hairs.

_Halberd-shaped._ Like an arrow-head, but with the basal lobes pointing outward nearly at right angles. Page XII.

_Heartwood._ The dead central portion of the trunk or large branch of a tree.

_Hirsute._ Covered with rather coarse or stiff hairs.

_Hoary._ Gray-white with a fine, close pubescence.

_Homogeneous._ Uniform; composed of similar parts or elements.

_Hybrid._ A cross between two nearly related species, formed by the action of the pollen of one upon the pistil of the other, yielding an intermediate form.

_Imbricate._ Overlapping, like the shingles on a roof.

_Indehiscent._ Not opening by valves or slits; remaining persistently closed.

_Indigenous._ Native and original to a region.

_Inflorescence._ The flowering part of a plant, and especially its arrangement.

_Internode._ The portion of a stem between two nodes.

_Involucral._ Pertaining to an involucre.

_Involucre._ A circle of bracts surrounding a flower or cluster of flowers.

_Keeled._ With a central ridge like the keel of a boat.

_Laciniate._ Cut into narrow, pointed lobes.

_Lanceolate._ Lance-shaped, broadest above the base and tapering to the apex, but several times longer than wide. Page xii.

_Lateral._ Situated on the side of a branch.

_Leaf._ The green expansions borne by the branches of a tree, consisting of a blade with or without a petiole.

_Leaflet._ One of the small blades of a compound leaf.

_Leaf-scar._ The scar left on a twig by the falling of a leaf. Page XVI.

_Legume._ A pod-like fruit composed of a solitary carpel and usually splitting open by both sutures (_Leguminosae_).

_Lenticels._ Corky growths on young bark which admit air to the interior of a twig or branch.

_Linear._ Long and narrow, with parallel edges (as pine needles). Page XII.

_Lobe._ Any division of an organ, especially if rounded.

_Lobed._ Provided with a lobe or lobes. Page XIII.

_Lustrous._ Glossy; shining.

_Membranaceous._ Thin and somewhat translucent.

_Midrib._ The central vein of a leaf or leaflet.

_Monoecious._ Unisexual, with staminate and pistillate flowers on the same individual.

_Mucilaginous._ Slimy; resembling or secreting mucilage or gum.

_Mucronate._ Tipped with a small, abrupt point. Page XII.

_Naked_. Lacking organs or parts which are normally present in related species or genera.

_Naturalized_. Said of introduced plants which are reproducing by self-sown seeds.

_Nectariferous_. Producing nectar.

_Node_. The place upon a stem which normally bears a leaf or whorl of leaves.

_Nut_. A hard and indehiscent, 1-celled, 1-seeded fruit.

_Nutlet_. A diminutive nut.

_Oblanceolate_. Lanceolate, with the broadest part toward the apex. Page XII.

_Oblique_. Slanting, or with unequal sides.

_Oblong_. Longer than broad, with sides approximately parallel. Page XII.

_Obovale_. Ovate, with the broadest part toward the apex. Page XII.

_Obovoid_. An ovate solid with the broadest part toward the apex.

_Obtuse_. Blunt or rounded at the apex. Page XII.

_Opaque_. Dull; neither shining nor translucent.

_Opposite_. Said of leaves, branches, buds, etc., on opposite sides of a stem at a node.

_Orbicular_. Circular. Page XII.

_Oval_. Broadly elliptical. Page XII.

_Ovary_. The part of a pistil that contains the ovules. Page XIII.

_Ovate_. Egg-shaped, with the broad end basal. Page XII.

_Ovoid_. Solid ovate or solid oval.

_Ovule_. The part of a flower which after fertilization becomes the seed.

_Palmate_. Radiately lobed or divided; hand-shaped.

_Panicle_. A loose, irregularly compound inflorescence with pedicellate flowers. Page XIV.

_Paniculate_. Arranged in panicles or resembling a panicle.

_Papilionaceous_. Butterfly-like, as in flowers of the _Leguminosae_.

_Pedicel_. The stalk of a single flower in a compound inflorescence.

_Pedicellate_. Borne on a pedicel.

_Peduncle_. A primary flower-stalk, supporting either a cluster or a solitary flower.

_Pendent._ Hanging downward.

_Pendulous._ More or less hanging or declined.

_Perfect._ Said of a flower with both stamens and pistil. Page XIII.

_Perianth._ The calyx and corolla of a flower considered as a whole.

_Persistent._ Long-continuous, as leaves through the winter, calyx on the fruit, etc.

_Petal._ One of the divisions of a corolla. Page XIII.

_Petiolate._ Having a petiole.

_Petiole._ The stem or stalk of a leaf.

_Petiolulate._ Having a petiolule.

_Petiolule._ The stem or stalk of a leaflet.

_Pilose._ Hairy with long, soft hairs.

_Pinnate._ Compound, with the leaflets arranged along both sides of a common petiole.

_Pistil._ The seed-bearing organ of a flower, normally consisting of ovary, style and stigma. Page XIII.

_Pistillate._ Provided with a pistil, but usually without stamens.

_Pith._ The softer central part of a twig or stem. Page XVI.

_Pollen._ The fecundating grains borne in the anther.

_Polygamo-dioecious._ Sometimes perfect, sometimes unisexual, both forms borne on different individuals.

_Polygamo-monoecious._ Sometimes perfect, sometimes unisexual, both forms borne on the same individual.

_Polygamous._ Sometimes perfect, sometimes unisexual, both forms borne on the same or on different individuals.

_Pome._ A fleshy fruit, as the apple.

_Posterior._ The back side of a flower, next to the axis of inflorescence.

_Prickle._ A small spine growing from the bark.

_Puberulent._ Minutely pubescent.

_Puberulous._ Minutely pubescent.

_Pubescence._ A covering of short, soft hairs.

_Pubescent._ Covered with short, soft hairs.

_Punctate._ Dotted with translucent or colored dots or pits.

_Raceme._ A simple inflorescence of flowers on pedicels of equal length arranged on a common, elongated axis (rachis). Page XIV.

_Racemose._ Resembling a raceme.

_Rachis._ The central axis of a spike or raceme of flowers or of a compound leaf.

_Recurved._ Curved downward or backward.

_Reticulate._ Netted.

_Rough._ Harsh to the touch; pubescent.

_Rugose._ Wrinkled.

_Samara._ An indehiscent winged fruit.

_Sapwood._ The living outer portion of a trunk or large branch of a tree between the heartwood and the bark.

_Scales._ Small modified leaves, usually thin and scarious, seen in buds and cones; the flakes into which the outer bark often divides.

_Scaly._ Provided with scales.

_Scarious._ Thin, dry, membranaceous; not green.

_Scurfy._ Covered with small bran-like scales.

_Seed._ The ripened ovule.

_Sepal._ One of the divisions of a calyx. Page XIII.

_Serrate._ Toothed, the teeth sharp and pointing forward. Page XIII.

_Sessile._ Without a stalk.

_Shrub._ A bushy, woody growth, usually branched at or near the base, less than 15 feet in height.

_Simple._ Of one piece; not compound.

_Sinuate._ Strongly wavy. Page XIII.

_Sinuous._ In form like the path of a snake.

_Sinus._ The cleft or space between two lobes.

_Smooth._ Smooth to the touch; not pubescent.

_Spatulate._ Wide and rounded at the apex, but gradually narrowed downward. Page XII.

_Spike._ A simple inflorescence of sessile flowers arranged on a common, elongated axis (rachis). Page XIV.

_Spine._ A sharp woody outgrowth from a stem.

_Spray._ The aggregate of smaller branches and branchlets.

_Stamen._ The pollen-bearing organ of a flower, normally consisting of filament and anther. Page XIII.

_Staminate._ Provided with stamens, but usually without pistils.

_Staminodium_. A sterile stamen.

_Sterile_. Unproductive, as a flower without pistil, or a stamen without anther.

_Stigma_. The part of a pistil which receives the pollen. Page XIII.

_Stipules_. Leaf-like appendages on either side of a leaf at the base of the petiole.

_Stipule-scar_. The scar left by the fall of a stipule. Page XV.

_Striate_. Marked with fine longitudinal stripes or ridges.

_Strobile_. A cone.

_Style_. The part of a pistil connecting ovary with stigma. Page XIII.

_Sub_-. A prefix applied to many botanical terms, indicating somewhat or slightly.

_Subtend_. To lie under or opposite to.

_Sucker_. A shoot arising from a subterranean part of a plant.

_Superposed_. Placed above, as one bud above another at a node.

_Suture_. A junction or line of dehiscence.

_Terete_. Circular in cross-section.

_Terminal_. Situated at the end of a branch.

_Ternate_. In threes.

_Tetrahedral_. Having, or made up of, four faces (triangles).

_Thorn_. A stiff, woody, sharp-pointed projection.

_Tolerant_. Capable of enduring more or less heavy shade.

_Tomentose_. Densely pubescent with matted wool.

_Toothed_. With teeth or short projections.

_Torus_. The part of the axis of a flower which bears the floral organs.

_Transverse_. Said of a wood section made at right angles with the axis of the stem; across the grain.

_Tree_. Usually defined as a plant with a woody stem, unbranched at or near the base, reaching a height of at least 15 feet.

_Trunk_. The main stem of a tree.

_Turbinate_. Top-shaped.

_Umbel_. A simple inflorescence of flowers on pedicels which radiate from the same point. Page XIV.

_Umbellate_. Arranged in umbels.

_Undulate_. With a wavy margin or surface. Page XIII.

_Unisexual_. Of one sex, either staminate or pistillate; not perfect.

_Veins._ Threads of fibro-vascular tissue in a leaf, petal, or other flat organ.

_Villose_ or _Villous_. Covered with long, soft hairs.

_Viscid._ Glutinous; sticky.

_Whorl._ An arrangement of leaves or branches in a circle round an axis.

_Wood._ The hard part of a stem lying between the pith and the bark.

_Woolly._ Covered with long and matted or tangled hairs.

INDEX TO THE ARTIFICIAL KEYS

Summer Keys:

Key to the genera, xxi. Key to the species of Acer, 172. Key to the species of Aesculus, 194. Key to the species of Betula, 84. Key to the species of Carya, 66. Key to the species of Catalpa, 222. Key to the species of Cornus, 202. Key to the species of Fraxinus, 210. Key to the species of Juglans, 60. Key to the species of Picea, 18. Key to the species of Pinus, 4. Key to the species of Populus, 44. Key to the species of Prunus, 152. Key to the species of Pyrus, 142. Key to the species of Quercus, 96. Key to the species of Salix, 34. Key to the species of Ulmus, 122.

Winter Keys:

Key to the genera, xxvii. Key to the species of Acer, 174. Key to the species of Aesculus, 195. Key to the species of Betula, 85. Key to the species of Carya, 67. Key to the species of Catalpa, 223. Key to the species of Cornus, 203. Key to the species of Fraxinus, 211. Key to the species of Juglans, 61. Key to the species of Picea, 19. Key to the species of Pinus, 5. Key to the species of Populus, 45. Key to the species of Prunus, 153. Key to the species of Pyrus, 143. Key to the species of Quercus, 98. Key to the species of Salix, 34. Key to the species of Ulmus, 123.

INDEX TO THE TREES

Abies balsamea, 27.

Acacia, Three-thorned, 165.

Acer dasycarpum, 185. negundo, 193. nigrum, 183. pennsylvanicum, 177. platanoides, 189. pseudo-platanus, 191. rubrum, 187. saccharinum, 181, 185. saccharum, 181, 189. saccharum nigrum, 183. spicatum, 179.

Aesculus glabra, 199. hippocastanum, 197. hippocastanum, v. flòre plèno, 197.

Ailanthus, 171. glandulosa, 171.

Almondleaf Willow, 39.

Alternate-leaved Dogwood, 207.

Amelanchier canadensis, 149.

American Crab, 145. Elm, 127.

Arborvitae, 31.

Ash, Black, 221. Blue, 219. Green, 217. Mountain, 147. Red, 215. White, 213.

Ash-leaved Maple, 193.

Aspen, 49. Largetooth, 51.

Austrian Pine, 11.

Balm of Gilead, 53. Hairy, 55.

Balsam, 53, 55. Fir, 27.

Basswood, 201.

Beech, 93. Blue, 83. Water, 83. White, 93.

Betula alba papyrifera, 91. alleghanensis, 87. lenta, 87. lutea, 89. papyrifera, 91.

Birch, Black, 87. Canoe, 91. Cherry, 87. Gray, 89. Paper, 91. Sweet, 87. White, 91. Yellow, 89.

Bitternut Hickory, 79.

Black Ash, 221. Birch, 87. Cherry, 155. Gum, 209. Jack, 119. Locust, 169. Maple, 183. Oak, 115, 117. Pine, 11. Spruce, 23. Sugar Maple, 183. Walnut, 65. Willow, 37.

Blue Ash, 219. Beech, 83. Dogwood, 207.

Boxelder, 193.

Boxwood, 205.

Brittle Willow, 41.

Buckeye, Ohio, 199.

Bur Oak, 103.

Butternut, 63.

Buttonball-tree, 141.

Button-wood, 141.

Canada Plum, 161.

Canoe Birch, 91.

Carpinus caroliniana, 83.

Carya alba, 69, 73. amara, 79. cordiformis, 79. glabra, 75, 77. laciniosa, 71. microcarpa, 75. ovata, 69. porcina, 77. sulcata, 71. tomentosa, 73.

Castanea dentata, 95. sativa, v. americana, 95. vesca, v. americana, 95.

Catalpa, 227. bignonioides, 225, 227. catalpa, 227. Hardy, 225. speciosa, 225.

Cedar, Red, 33. White, 31.

Celtis occidentalis, 131.

Cercis canadensis, 167.

Cherry Birch, 87.

Cherry, Black, 155. Choke, 157. Pin, 159. Wild Red, 159.

Chestnut, 95. Oak, 107.

Chinquapin Oak, 107.

Choke Cherry, 157.

Coffeetree, 163. Kentucky, 163.

Cork Elm, 129.

Cornus alternifolia, 207. florida, 205.

Cottonwood, 57.

Crab, American, 145. Sweet, 145.

Crack Willow, 41.

Crataegus, 151. punctata, 150.

Dogwood, 205. Alternate-leaved, 207. Blue, 207. Flowering, 205.

Elm, American, 127. Cork, 129. Red, 125. Rock, 129. Slippery, 125. Water, 127. White, 127.

Fagus americana, 93. atropunicea, 93. ferruginea, 93. grandifolia, 93.

Fir, Balsam, 27. Scotch, 13.

Flowering Dogwood, 205.

Fraxinus americana, 213. lanceolata, 217. nigra, 221. pennsylvanica, 215, 217. pennsylvanica lanceolata, 217. pubescens, 215, quadrangulata, 219. sambucifolia, 221. virdis, 217.

Ginkgo, 3. biloba, 3.

Gleditsia triacanthos, 165.

Gray Birch, 89.

Green Ash, 217.

Gum, Black, 209.

Gymnocladus canadensis, 163. dioica, 163.

Hackberry, 131.

Hairy Balm of Gilead, 55.

Hard Maple, 181.

Hardy Catalpa, 225.

Haw, 151.

Hawthorn, 151.

Hemlock, 29.

Hickory, Bitternut, 79. Mocker Nut, 73. Pignut, 77. Shagbark, 69. Shellbark, 69, 71. Small Pignut, 75.

Hicoria alba, 73. glabra, 77. glabra, v. odorata, 75. laciniosa, 71. microcarpa, 75. minima, 79. odorata, 75. ovata, 69.

Hill's Oak, 115.

Honey Locust, 165.

Hornbeam, 81.

Horse-chestnut, 197.

Ironwood, 81.

Jack Pine, 9.

Judas-tree, 167.

Juglans cinerea, 63. nigra, 65.

Juniper, Red, 33.

Juniperus virginiana, 33.

Kentucky Coffeetree, 163.

King Nut, 71.

Largetooth Aspen, 51.

Larix americana, 17. laricina, 17.

Liriodendron tulipifera, 137.

Locust, 169. Black, 169. Honey, 165.

Lombardy Poplar, 59.

Maclura aurantiaca, 133. pomifera, 133.

Maidenhair Tree, 3.

Malus coronaria, 145.

Maple, Ash-leaved, 193. Black, 183. Black Sugar, 183. Hard, 181. Mountain, 179. Norway, 189. Red, 187. Rock, 181. Silver, 185. Soft, 185, 187. Striped, 177. Sugar, 181. Sycamore, 191.

Mocker Nut Hickory, 73.

Moosewood, 177.

Morus rubra, 135.

Mountain Ash, 147. Maple, 179.

Mulberry, Red, 135.

Nannyberry, 229.

Napoleon's Willow, 43.

Negundo aceroides, 193.

Nettle-tree, 131.

Northern Pin Oak, 115.

Norway Maple, 189. Pine, 15. Spruce, 25.

Nut, King, 71.

Nyssa multiflora, 209. sylvatica, 209.

Oak, Black, 115, 117. Bur, 103. Chestnut, 107. Chinquapin, 107. Hill's, 115. Northern Pin, 115. Pin, 111. Red, 109. Scarlet, 113. Shingle, 121. Swamp, 105. Swamp White, 105. White, 101. Yellow, 107, 117.

Ohio Buckeye, 199.

Osage Orange, 133.

Ostrya virginiana, 81.

Padus serotina, 155. virginiana, 157.

Paper Birch, 91.

Pepperidge, 209.

Picea abies, 25. alba, 21. canadensis, 21. excelsa, 25. mariana, 23. nigra, 23.

Pignut Hickory, 77. Small, 75.

Pin Cherry, 159. Oak, 111. Oak, Northern, 115.

Pine, Austrian, 11. Black, 11. Jack, 9. Norway, 15. Red, 15. Scotch, 13. Scrub, 9. White, 7.

Pinus austriaca, 11. banksiana, 9. divaricata, 9. laricio austriaca, 11. resinosa, 15. strobus, 7. sylvestris, 13.

Platanus occidentalis, 141.

Plum, Canada, 161. Red, 161.

Poplar, Lombardy, 59. Tulip, 137. White, 47.

Populus alba, 47. balsamifera, 53, 55. balsamifera candicans, 55. candicans, 55. deltoides, 57. dilatata, 59. fastigiata, 59. grandidentata, 51. monilifera, 57. nigra italica, 59. tremuloides, 49.

Prunus americana, v. nigra, 161. nigra, 161. pennsylvanica, 159. serotina, 155. virginiana, 157.

Pyrus americana, 147. coronaria, 145.

Quercus acuminata, 107. alba, 101. Alexanderi, 107. bicolor, 105. coccinea, 113. ellipsoidalis, 115. imbricaria, 121. macrocarpa, 103. marilandica, 119. muhlenbergii, 107. palustris, 111. platanoides, 105. rubra, 109. velutina, 117.

Red Ash, 215. Cedar, 33. Cherry, Wild, 159. Elm, 125. Juniper, 33. Maple, 187. Mulberry, 135. Oak, 109. Pine, 15. Plum, 161.

Redbud, 167.

Robinia pseudo-acacia, 169.

Rock Elm, 129. Maple, 181.

Salisburia adiantifolia, 3.

Salix, 35. amygdaloides, 39. babylonica, 43. fragilis, 41. nigra, 37.

Sassafras, 139. officinale, 139. sassafras, 139. variifolium, 139.

Scarlet Oak, 113.

Scotch Fir, 13. Pine, 13.

Scrub Pine, 9.

Serviceberry, 149.

Shagbark Hickory, 69.

Sheepberry, 229.

Shellbark Hickory, 69, 71.

Shingle Oak, 121.

Silver Maple, 185.

Slippery Elm, 125.

Small Pignut Hickory, 75.

Soft Maple, 185, 187.

Sorbus americana, 147.

Spruce, Black, 23. Norway, 25. White, 21.

Striped Maple, 177.

Sugar Maple, 181. Black, 183.

Swamp Oak, 105. White Oak, 105.

Sweet Birch, 87. Crab, 145.

Sycamore, 141. Maple, 191.

Tamarack, 17.

Thorn, 151.

Thorn-apple, 151.

Three-thorned Acacia, 165.

Thuja occidentalis, 31.

Tilia americana, 201.

Toxylon pomiferum, 133.

Tree, Maidenhair, 3. of Heaven, 171.

Tsuga canadensis, 29.

Tulip Poplar, 137.

Tulip-tree, 137.

Ulmus americana, 125, 127. fulva, 125, pubescens, 125. racemosa, 129. Thomasi, 129.

Viburnum lentago, 229.

Walnut, Black, 65.

Water Beech, 83. Elm, 127.

Weeping Willow, 43.

Whistlewood, 177.

White Ash, 213. Beech, 93. Birch, 91. Cedar, 31. Elm, 127. Oak, 101. Oak, Swamp, 105. Pine, 7. Poplar, 47. Spruce, 21.

White-wood, 137.

Wild Red Cherry, 159.

Willow, 35. Almondleaf, 39. Black, 37. Brittle, 41. Crack, 41. Napoleon's, 43. Weeping, 43.

Yellow Birch, 89. Oak, 107, 117.