1342

ARBORETUM AND FRUTICETUM.

PART III.

Plagianthus divaricatus Forst., t. 43., is a native of New Zealand, and was introduced in 1822.It is tolerably hardy ; a plant having lived with us at Bayswater, with very little protection, since1829. P. s ido'ides Hook. Hot. Mag., t. 3396., is a twiggy shrub, from 2 ft. to 3ft high, probably alsoas hardy as the other. Both species flower in April.

Cluyt'm a iaternoldes Bot. Mag., t. 1321., has been an inhabitant of our green-houses since 1692. Itis a native of the Cape of Good Hope, and would probably stand against a conservative wall.

CHAP. c.

OF THE HARDY LIGNEOUS PLANTS OF THE ORDER URTICA'CEiE.

These are included in five genera, which have their names and characters

below.

JTo'rus Tourn. Flowers unisexual; those of the 2 sexes, in most species,upon the same plant; in M. nigra Pair., and, according to Gronovius ( Virg.,146.), in M. riibra L., upon distinct plants: according to Kalin (Act. Suec.,1776), the sexes of M. riibra L. are polygamous.—Male flowers disposedin a drooping, peduncled, axillary spike. Calyx of 4 equal sepals, imbri-cate in mstivation, expanded in flowering. Stamens 4. A rudiment of apistil is present. — Female flowers in ovate erect spikes. Calyx of 4leaves, in opposite pairs, the outer pair the larger, all upright and persistent,becoming pulpy and juicy. Ovary of 2 cells, one including one pendulousovule, the other devoid of any. Stigmas 2, long. In the state of ripeness,each ovary is a fleshy and juicy utricle, and is covered by the fleshyand juicy calyx: the aggregate of the ovaries and the calyxes from aspike of flowers constitutes what is termed a mulberry. Seed pendulous— Species several; natives of Asia, south of Europe, and North America.Trees. Sap white. Leaves alternate, large, mostly lobed, and rough ; thefavourite food of the silk-moth (Bombyx mori F.) in its caterpillar state.(Chiefly from T. Nees ah Esenbcck, Gen. PL FI. Germ.)

Broussone'tli L’Herit. Flowers unisexual; those of the two sexes upondistinct plants. — Male flowers in pendulous cylindrical catkins; eachflower in the axil of a bractea. Calyx shortly tubular, then 4-parted. Sta-mens 4, elastic.—Female flowers in peduncled, axillary, upright globularheads. Calyx tubular, its tip with 3—4 teeth. Ovary within an integumentthat arises from the bottom of the calyx. Style lateral, prominent. Stigmataper. Fruit club-shaped, proceeding from the bottom of the calyx, andextended much beyond its tip; and consisting of the integument in whichthe ovary was enclosed, and now become very juicy; and of a 1-seededoval utricle with a crustaceous integument, and enclosed within the juicy,integument.— Species 1, native to Japan and the isles of the Pacific Ocean.A tree, with leaves large, lobed or not, and hairy. (Du Hamel, Traite desArbres, ed. nouv.; and the Penny Cyclopcedia.)

Maclu'rA Nuttall. Flowers unisexual; in M. aurantiaca Nutt., and M.tinctoria D. Don, those of the two sexes upon distinct plants; if not so inthe rest, then upon the same plant. What follows relates to M. aurantiacaNutt. — Male flowers in a very short almost sessile racemose panicle of 12or more flowers. Calyx 4-parted. Stamens 4, in some instances 3. —Female flowers closely aggregate upon an axis, and forming a globular headthat is borne upon a short axillary peduncle. Calyx oblong, urceolar,apparently with 4 lobes at the tip : it includes the ovary, which is situatedabove its base, and is terminated by a style that is thread-shaped, downy,and protruded beyond the calyx to the length of nearly 1 in. The ovarybecomes an achenium about § in. long, half as much broad, compressed,oval, with the tip blunt and unsymmetrical from an indentation on one sidein which the style had been attached. — A tree, native of North America.Spiny : spines axillary. Sap white. Leaves alternate, ovate. Stipulesminute, deciduous. (Nuttall; Gard. Mag., vol. xi. p. 312—316., and vol.xii. p. 210.; and observation.)