2062

ARBORETUM AND FIUJTICETUM.

I'AIIT III,

creases in size, the pines or firs surrounding it should have their brunchescut in, or the trees should be cut down, so as to allow the former room toexpand on every side, and to increase its power of resisting cold and wind,as it increases in size. Ultimately, a space of such dimensions might be leftround it as to admit of a spectator looking at the top of the tree, at an angleof vision of from 30° to 35°. We mention this angle of vision, becauseexperience proves that no tree or other object can be seen to the greatest ad-vantage when the angle of vision is either much greater, or much less, thanfrom 30° to 35°. The casuarinas, when grown in pots, thrive well in equalparts of sand, loam, and peat: but, in the open ground, a sandy loam, witha dry subsoil, would probably suit them best; because, in such a soil, theywould probably not make more wood than they could ripen before winter.They are all propagated by seeds, but would probably succeed by cuttings ofthe points of the shoots, in sand, under a bell-glass.

CHAP. CXI

OF THE HAIIDY LIGNEOUS PLANTS OF THE ORDER QNKTA'CEX.

ETphedra Tourn. Devoid of obvious leaves. Leaves scale-like, opposite,in pairs; the direction of the pairs decussating. Flowers unisexual; thoseof the two sexes upon distinct plants.—Male. Flowers in axillary groups.Flowers in the group opposite, in pairs; the pairs decussate in direction ;each pair subtended by a perfoliate bractea. Calyx tubular, bifid in theupper part; first including, then surrounding, a straight column situated atits base, extended beyond its tip, and there divided into 2—8 short pedicels,proper to as many anthers : each anther has two cells, and each cell opensby a terminal hole. — Female. Flowers borne about the terminal parts ofa branch, or of branches; in pairs . the pairs 1—2 together, at the tips ofaxillary peduncles ; or 3 together at the tip of a branch. Each flowerconsists of an ovule, plano-convex, upright, perfoliated at the tip, and ter-minated by a style-like hollow process, formed from the secundine of thenucleus. The ovules are disposed 2 together, with their flat faces approx-imate ; and the 2 are bracteated by perfoliate decussate bracteas. Eachovule, if not abortive, becomes a seed. The seeds are partly invested withthe uppermost and upper of the bracteas, enlarged, and rendered fleshy.Embryo in the centre of fleshy albumen. Radicle uppermost. — Speciesfew, natives of the temperate parts of Europe , Asia, and Africa. Shrubs;much branched. Stem and branches jointed, and separable at the joints.(T. Nces ab Esenb. Gen. PI. FI. Ger.; Lindl. Nat. Syst. But. ; and obser-vation.)

Genus I

E'PIIEDUA L. The Ephedra. Lin. Syst. Dice'cia Monadelphia.

Identification. Lin. Gen., 1136.; Reich., 1242.; Schrcb., 1554.; Tourn., 447.; N. Du Ham., 3.

p. 17.

Derivation. From ephedra, the Greek name for the //ippdrls, or Horsetail , which it resembles.

Description, Sjc. Low shrubs ; evergreen, from the colour of the bark oftheir branches, and in that respect resembling the genera Casuarina and 7tqni-setuin. They are natives of the south of Europe, Barbary, and Siberia , oilthe sea shore", or in saline or sandy wastes; and they have been but little sub-jected to cultivation. They might, however, be used in ornamental sceneryas evergreens, and even cultivated for their fruit; which, in their native coun-