GEN. IV. CORYLUS. HASEL-NUT. 1. C. Avellana. the fruit. Common H. Involucre about the length of GEN. V. CARPINUS. HORNBEAM. 1. C. Betulus. Common H. Involucre 3-lobed, middle lobe the longest. 1. U. pilulifera. Roman N. The fertile flowers in globular heads. 2. U. dioica. Great N. Spikes of flowers much branched, longer than the leaf-stalks; root perennial. 3. U. urens. Small N. Spikes nearly simple, shorter than the leaf-stalks; root annual. GEN. II. PARIETARIA. PELLITORY OF THE WALL. 1. P. officinalis. Common P. GEN. III. HUMULUS. HOP. 1. H. Lupulus. Common H. GEN. IV. ULMUS. ELM. 1. U. suberosa. Common E. Seminiferous cavity of the fruit chiefly above the middle, and extending almost to the notch. campestris (not Lin.). major. glabra. 2. U. campestris (Lin.). Broad-leaved E., or Wych-hasel. Seminiferous cavity chiefly below the middle, and distant from the notch. montana. 1. C. demersum. Common H. Fruit with spines or tubercles near the base; style longish. 2. C. submersum. Unarmed H. Fruit without spines or tubercles; style very short. IX. EUPHORBIACEÆ. 1. Perianth 3-partite; stamens 9-12; 2. Involucre of 1 piece, but no perianth; 3. Perianth 4-partite; stamens 4; cap sule 6-seeded Euphorbia. Buxus. MERCURY. 1. M. perennis. Perennial, or Dog's M. Perennial; leaves 1. E. Peplis. Purple S. Leaves with stipules; stems glaucous, purplish, procumbent. Leaves without stipules. A. Bracts united at the base. 2. E. amygdaloides. Wood S. Glands of the involucre yellow, with two horns; leaves obtuse, obovate. 3. E. Characias. Red shrubby S. Glands of the involucre purple, bluntly lunate; leaves lanceolate. B. Bracts distinct at the base. I. Glands of the involucre roundish, not angular. 4. E. Hiberna. Irish S. Leaves ovate, entire, not serrated; capsule warted. Leaves serrated. 5. E. helioscopia. Sun S. Leaves obovate; capsule smooth and shining. Capsules warted or hairy. 6. E. platyphylla. Broad-leaved warted S. Bracts cordate; leaves obovate, broad. stricta. 7. E. palustris. Marsh S. Leaves lanceolate. pilosa. coralloides. II. Glands angular or horned. a. Glands of the involucre roundish, with 2 long horns. 8. E. Esula. Leafy-branched S. branches; seeds smooth. 9. E. exigua. Umbel of many Dwarf S. Umbel of a few (3) forked branches; seeds angular, wrinkled. b. Glands of the involucre lunate. 10. E. Cyparissias. Cypress S. Leaves very narrow. Seeds rough. 12. E. Lathyris. Caper S. Glands of the involucre bluntly lunate; carpels smooth. Glands of the involucre with 2 long points. 13. E. Portlandica. Portland S. Bracts triangular-heartshaped. 14. E. Peplus. Petty S. Umbel of about 3 principal forked branches; bracts ovate. 1. B. sempervirens. Common B. Leaves oval, shining. 1. E. nigrum. Black C. Margins of the leaves bent back wards; berries clustered. XI. CALLITRICHACEÆ. 1. Leaves opposite, simple, entire GEN. I. Callitriche. 1. C. verna. base. CALLITRICHE. WATER-STARWORT. Vernal W. Flower-stalks with 2 bracts at the 2. C. autumnalis. Autumnal W. Flower-stalks without bracts. pedunculata. aquatica. GEN. I. BRYONIA. BRYONY. 1. B. dioica. Red-berried B. Leaves rough on both sides; berries red; corolla whitish. 1. E. septangulare. Jointed P. Flowers 4-cleft; stamens 4; leaves pellucid. II. GRAMINACEÆ. THE flowers of a Grass differ in some important particulars from ordinary flowers. The terms calyx and corolla are not applicable to the envelopes by which the stamens and ovary of a Grass are enclosed and protected. Different terms are applied to them by different authors, but it is only necessary to describe here those which are made use of in this book. If a single floret of a Grass be examined, the stamens and ovary will be found to be immediately enclosed in what might be mistaken for sepals composing a calyx. It will be seen, however, that they do not arise at the same level on the stem, but overlap below, and are, properly speaking, not sepals, but bracts; to each of these the term glumella is applied, and a floret of a Grass consists merely of stamens and ovary, enclosed in one or more of these bracts, called glumellæ. A spikelet is formed by one, two, three, or more florets, at the base of which other bracts are usually found, exactly like glumellæ in appearance, and differing from them only in this particular, that they do not immediately enclose the stamens and ovary, but are placed at the base of spikelets. These bracts are called glumes. In two instances no such bracts are present, in others only one is found, but most commonly two glumes are to be found at the base of each spikelet. If the spikelets are simple and sessile upon the rachis or mainstalk, the inflorescence forms a spike, more or less dense; if they are themselves stalked, we have a raceme; or if the stalks are branched, a panicle. |