Part 154 (1/2)

Tribe I. BETULEae. Flowers in scaly catkins, 2 or 3 to each bract.

Sterile catkins pendulous. Stamens 2--4, and calyx usually 2--4-parted.

Fertile flowers with no calyx, and no involucre to the compressed and often winged small nut. Ovary 2-celled, 2-ovuled.

1. Betula. Stamens 2, bifid. Fertile scales thin, 3-lobed, deciduous with the nuts.

2. Alnus. Stamens 4. Fertile scales thick, entire, persisting after the nuts have fallen.

Tribe II. CORYLEae. Sterile catkins pendulous, with no calyx; stamens 3 or more to each bract and more or less adnate to it, the filaments often forked (anthers 1-celled). Fertile flowers in a short ament or head, 2 to each bract, and each with one or more bractlets which form a foliaceous involucre to the nut. Ovary 2-celled, 2-ovuled.

[*] Bract of staminate flower furnished with a pair of bractlets inside; fertile flowers few.

3. Corylus. Involucre leafy-coriaceous, enclosing the large bony nut.

[*][*] Bract of staminate flower simple; fertile flowers in short catkins; nut small, achene-like.

4. Ostrya. Each ovary and nut included in a bladdery and closed bag.

5. Carpinus. Each nut subtended by an enlarged leafy bractlet.

Tribe III. QUERCINEae. Sterile flowers with 4--7-lobed calyx and stamens indefinite (3--20). Fertile flowers 1 or few, enclosed in a cupule consisting of consolidated bracts, which becomes indurated (scaly or p.r.i.c.kly) and surrounds or encloses the nut.

[*] Sterile flowers in slender catkins.

6. Quercus. Cupule 1-flowered, scaly and entire; nut hard and terete.

7. Castanea. Cupule 2--4-flowered, forming a p.r.i.c.kly hard bur, 2--4-valved when ripe.

[*][*] Sterile flowers in a small head.

8. f.a.gus. Cupule 2-flowered, 4-valved, containing 2 sharply triangular nuts.

1. BeTULA, Tourn. BIRCH.

Sterile flowers 3, and bractlets 2, to each s.h.i.+eld-shaped scale or bract of the catkins, consisting each of a calyx of one scale bearing 4 short filaments with 1-celled anthers (or strictly of two 2-parted filaments, each division bearing an anther-cell). Fertile flowers 2 or 3 to each 3-lobed bract, without bractlets or calyx, each of a naked ovary, becoming a broadly winged and scale-like nutlet (or small samara) crowned with the two spreading stigmas.--Outer bark usually separable in sheets, that of the branchlets dotted. Twigs and leaves often spicy-aromatic. Foliage mostly thin and light. Buds sessile, scaly.

Sterile catkins long and drooping, terminal and lateral, sessile, formed in summer, remaining naked through the succeeding winter, and expanding their golden flowers in early spring, with or preceding the leaves; fertile catkins oblong or cylindrical, peduncled, usually terminating very short 2-leaved early lateral branches of the season. (The ancient Latin name, of Celtic origin.)

[*] _Trees, with brown or yellow-gray bark, sweet-aromatic as well as the twigs, membranaceous and straight-veined Hornbeam-like leaves heart-shaped or rounded at base, on short petioles, and sessile very thick fruiting catkins; their scales about equally 3-cleft, rather persistent; wing of fruit not broader than the seed-bearing body._

1. B. lenta, L. (CHERRY B. SWEET or BLACK BIRCH.) _Bark_ of trunk _dark brown, close_ (outer layers scarcely laminate), very sweet-aromatic; leaves ovate or oblong-ovate from a more or less heart-shaped base, ac.u.minate, sharply and finely doubly serrate all round, when mature s.h.i.+ning or bright green above and glabrous except on the veins beneath; _fruiting catkins oblong-cylindrical_ (1--1' long), the scales with short and _divergent lobes_.--Rich woodlands, Newf. to N. Del., and south in the mountains, west to Minn., and S. Ind. Tree 50--75 high, with reddish bronze-colored spray; wood rose-colored, fine-grained, valuable for cabinet-work.

2. B. lutea, Michx. f. (YELLOW or GRAY BIRCH.) _Bark_ of trunk _yellowish- or silvery-gray, detaching in very thin filmy layers_, within and the twigs much less aromatic; leaves (3--5' long) slightly or not at all heart-shaped and often narrowish toward the base, duller-green above and usually more downy on the veins beneath; fruiting catkins _oblong-ovoid_ (1' or less in length, 6--9” thick), the thinner scales (5--6” long) twice as large as in n. 1, and with narrower _barely spreading lobes_.--Rich moist woodlands, Canada and N. Eng. to Del., west to Minn.; also along high peaks to Tenn. and N. C. Often 60--90 high at the north; wood whiter and less valuable.

[*][*] _Trees, with chalky-white bark separable in thin sheets, ovate or triangular leaves of firmer texture, on long slender petioles; fruiting catkins cylindrical, usually hanging on rather slender peduncles; their scales glabrous, with short diverging lobes, freely deciduous; wing of the fruit much broader than its body._

3. B. populiflia, Ait. (AMERICAN WHITE BIRCH. GRAY BIRCH.) Trunk usually ascending (15--30 high); _leaves triangular_ (deltoid), _very taper-pointed_ (usually abruptly), truncate or nearly so at the broad base, _smooth and s.h.i.+ning both sides_, except the resinous glands when young. (B. alba, var. populifolia, _s.p.a.ch_.)--Poor sandy soils, N.

Brunswick to Del., west to L. Ontario. Bark much less separable than the next; leaves on slender petioles, tremulous as those of the aspen.

4. B. papyrifera, Marshall. (PAPER or CANOE BIRCH. WHITE BIRCH.) _Leaves ovate, taper-pointed_, heart-shaped or abrupt (or rarely wedge-shaped) at base, _smooth and green above_, pale, glandular-dotted, and a little hairy on the veins beneath, sharply and unequally doubly serrate, 3--4 times the length of the petiole. (B. papyracea, _Ait._)--Rich woodlands and stream-banks, N. Eng. to N. Penn., N. Ill., and Minn., and far north and westward. Tree 50--75 high, with bark freely splitting into paper-like layers.--Var. MINOR, Tuckerman, is a dwarf form of the alpine region of the White Mts.