Herbs, shrubs, or trees, with monoecious or dioecious (or, in the Elms, sometimes perfect) flowers, with a regular calyx free from the 1-2-celled ovary which becomes a 1-seeded fruit. Stamens opposite the lobes of the calyx. This Order is divided into four well-marked Suborders.
Trees, with alternate simple leaves, and deciduous small stipules. Flowers often perfect. Styles 2. Fruit a samara winged all round, or a drupe.
* Fruit a samara; anthers extrorse.
1. Ulmus. Flowers in lateral clusters, earlier than the leaves, purplish or greenish-yellow. Calyx bell-shaped, 4-cleft. Stamens 4-9; the filaments long and slender. Ovary 2-celled, but the samara only 1-seeded. Stigmas 2.
* * Fruit a drupe; anthers introrse.
2. Celtis. Flowers greenish, polygamous, the pistillate solitary or in pairs, appearing with the leaves. Calyx 5-6-parted, persistent. Stamens 5-6. Stigmas 2, long and pointed and recurved. Ovary 1-ovuled.
Flowers monoecious or dioecious, crowded in catkin-like spikes or heads, the whole pistillate catkin becoming an aggregate fruit from the enlargement of the calyx in the several flowers. Calyx 4-parted. Stamens 4. Ovary 2-celled, 1 cell eventually disappearing. Styles 2.
8. Morns. Pistillate and staminate flowers in separate catkins. Trees with milky juice and rounded leaves. Staminate spikes slender.
Herbs with, watery juice and opposite or alternate leaves, often beset with stinging hairs. Flowers monoecious or dioecious, in spikes or racemes. Stamens as many as the sepals. Style only 1, Ovary 1-celled. Fruit an achene.
4. Urti'ca. Leaves opposite. Plant beset with stinging hairs. Sepals 4 in both sterile and fertile flowers. Stamens 4. Stigma a small sessile tuft. Achene flat, enclosed between the 2 larger sepals. Flowers greenish.
5. Laport'ea. Leaves alternate. Plant beset with stinging hairs Sepals 5 in the sterile flowers, 4 in the fertile, 2 of them much smaller than the other 2. Stigma awl-shaped. Achene flat, very oblique, reflexed on its winged pedicel.
6. Pil'ea. Leaves opposite. Whole plant very smooth and semi-transparent. Sepals and stamens 3-4. Stigma a sessile tuft.
7. Boehmeria. Leaves mostly opposite. No stinging hairs. Sepals and stamens 4 in the sterile flowers. Calyx tubular or urn-shaped in the fertile ones, and enclosing the achene. Stigma long and thread-like.
8. Parietaria. Leaves alternate, entire, 3-ribbed. No stinging hairs.
Flowers polygamous, in involucrate-bracted cymose axillary clusters. Calyx of the pistillate flowers tubular or bell-shaped, 4-lobed. Stigma tufted. Staminate flowers nearly as in the last.
Rough herbs with watery juice and tough bark. Leaves opposite and palmately divided or lobed. Flowers dioecious. Sterile ones in compound racemes; stamens 5; sepals 5. Fertile ones in crowded clusters; sepal only 1, embracing the achene. Stigmas 2.
9. Can'nabis. A rather tall rough plant with palmately compound leaves of 5-7 linear-lanceolate serrate leaflets. Fertile flowers spiked-clustered. 16. Hu mulus. Leaves 3-5-lobed. Plant climbing. Fertile flowers in a short spike, forming a membranaceous catkin in fruit.
L. Elm. 1. U. fulva, Michx. (Red or Slippery Elm.) Flowers nearly sessile. Leaves very rough above, taper-pointed. Buds downy with rusty hairs. A medium-sized tree, with mucilaginous inner bark.
2. U. Americana, L. (American or White Elm.) Leaves not rough above, abruptly pointed. Flowers in drooping pedicels. Buds glabrous. A large ornamental tree, with drooping branchlets. - Moist woods.
3. U. racemo'sa, Thomas. (Corky White Elm.) Re-sembling the last, but the bud-scales are dowmy-ciliate, the branches corky, and the flowers racemed. - Chiefly along roadsides and borders of fields.
2. Cel'tis. L. Nettle-Tree. Hackberry. C. occidenta'lis, L. (Sugarberry.) A small tree of Elm-like aspect. Leaves reticulated, ovate, taper-pointed, serrate, more or less oblique at the base. Fruit as large as a pea, dark-purple when ripe, the flesh thin. - Low grounds; a few trees here and there through Ontario.
1. M. ru'bra, L. (Red Mulberry.) Leaves heart-ovate, rough above, downy beneath, pointed. Fruit red, turning dark-purple, long. - Niagara district, and south-westward.
2. M. alba, L. (White M.) Leaves smooth and shining. Fruit whitish. - S. W. Ontario.
1. U. gra'cilis, Ait. Stem slender, 2-6 feet high. Leaves ovate-lanceolate, pointed, serrate, 3-5-nerved from the base, nearly smooth, the long petioles with a few bristles. Flower-clusters in slender spikes. - Moist ground and along fences.
2. U. dioi'ca, L. (Stinging Nettle.) Plant bristly with very stinging hairs. Leaves ovate, cordate, very deeply serrate. Spikes branching. - Waste places.
3. U. U'rens, L. Leaves elliptical or ovate, coarsely and deeply serrate with spreading teeth, petioled. Flower-clusters 2 in each axil, composed of both staminate and pistillate flowers. - Waste grounds, Atl. Prov.
Gaudichaud. Wood-Nettle. L. Canadensis, Gaudichaud. Stem 2-3 feet high. Leaves large, ovate, long-petioled, a single 2-cleft stipule in the axil - Moist woods.
Lindl. Richweed. Clearweed. P. pu'mila, Gray. Stem 3-18 inches high. Leaves ovate, coarsely-toothed, 3-ribbed. - Cool moist places.
B. cylin'drica, Willd. Stem 1-3 feet high, smoothish. Leaves ovate-oblong or ovate-lanceolate, serrate, 3-nerved, long-petioled. Stipules separate. - Moist shady places.
Tourn. Pellitory. P. Pennsylvan'ica, Muhl. A low annual, simple or sparingly branched, minutely downy. Leaves oblong-lanceolate, thin, veiny, roughish with opaque dots. - Usually in crevices of limestone rocks; not very common.
C. sati'va, L. (Hemp.) Common everywhere along roadsides and in waste places.
L. Hop. H. Lu'pulus, L. (Common Hop.) A twining perennial. Leaves heart-shaped, mostly 3-5-lobed, petioled. Calyx of fertile flower a single sepal'. In fruit the calyx, achene, etc., sprinkled with yellow resinous grains, which give the hop its taste and smell.