'1062 ARBORETUM AND FRUT1CETUM. PART 111. 



creases in size, the pines or firs surrounding it should have their branches 

 cut in, or the trees should be cut down, so as to allow the former room to 

 expand 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 left 

 round it as to admit of a spectator looking at the top of the tree, at an angle 

 oi' vision of from 30° to 35°. We mention this angle of vision, because 

 experience 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, than 

 from 30° to 35°. The casuarinas, when grown in pots, thrive well in equal 

 parts of sand, loam, and neat : but, in the open ground, a sandy loam, with 

 a dry subsoil, would probably suit them best ; because, in such a soil, they 

 would probably not make more wood than they could ripen before winter. 

 They are all propagated by seeds, but would probably succeed by cuttings of 

 the points of the shoots, in sand, under a bell-glass. 



CHAP. CXI. 



OF THE HARDY LIGNEOUS PLANTS OF THE ORDER GNETA y CEJ2. 



Ephedra Tourn. Devoid of obvious leaves. Leaves scale-like, opposite, 

 in pairs; the direction of the pairs decussating. Flowers unisexual; those 

 of 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 the 

 upper part ; first including, then surrounding, a straight column situated at 

 its 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 opens 

 by a terminal hole. — Female. Flowers borne about the terminal parts of 

 a branch, or of branches; in pairs : the pairs 1 — 2 together, at the tips of 

 axillary peduncles ; or 3 together at the tip of a branch. Each flower 

 consists of an ovule, plano-convex, upright, perfoliated at the tip, and ter- 

 minated by a style-like hollow process, formed from the secundine of the 

 nucleus. The ovules are disposed 2 together, with their flat faces approx- 

 imate; and the 2 are bracteated by perfoliate decussate bracteas. Each 

 ovule, if not abortive, becomes a seed. The seeds are partly invested with 

 the uppermost and upper of the bracteas, enlarged, and rendered fleshy. 

 Embryo in the centre of fleshy albumen. Radicle uppermost. — Species 

 few, 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 Escnb. Gen. PL Fl. Ger.; Lindl. Nat. Syst. Bot.; and obser- 

 vation.) 



Genus I. 



AJ 



ETHEDRA L. The Ephedra. Lin. Syst. DioeVia Monadelphia. 



Identification. Lin. Gen., 1136. ; Reich., 1242. ; Schreb., 1554. ; Tourn., 447. ; N. Du Ham., 8. 



p. 17. 

 Derivation I ttm cpkcdra,thc Greek name for the 7/ippuris, or Horsetail, which it resembles. 



Description, $c. Low shrubs; evergreen, from the colour of the bark of 



their branches, and in that respect resembling the genera Casuarina and 2?qui- 



n. They are natives of the south of Europe, Barbary, and Siberia, on 



the sea cliore, or in saline «r sandy wastes; and they have been but little sub- 



i to cultivation. They might, however, be used in ornamental scenery 



<;ns, and even cultivated for their fruit; which, in their native coun- 



