_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.