_Cupressus_ (Cypress). _Monœcious._ The cones are spherical; the cone-scales shield-like, generally five-cornered and woody (Fig. 270), each having many seeds. The leaves are scale-like.--_Thuja. Monœcious._ Cones oblong. The cone-scales are dry, as in the Cypress, but leathery and imbricate, and not shield-like; each cone-scale bears 2–3 seeds. The leaves are most frequently dimorphic; those leaves which are situated on the edges of the flat branches are compressed, and only these bear buds, which are developed with great regularity, generally alternately, on both sides of the branch; those which are situated on the flattened surfaces are pressed flat and broad, and never bear branches (Fig. 271). Along the central line of each leaf there is a resin-canal (Fig. 271).--~_Chamæcyparis_, _Callitris_, _Libocedrus_, _Thujopsis_ (1 species: _T. dolabrata_; in Japan).~ [Illustration: FIG. 273.--Branch of Juniper with “berry-cones.”] [Illustration: FIG. 274.--_Cupressus lawsoniana._ Longitudinal section through female cone. Two ovules (_ov_) are bisected; _f_ ovuliferous scales.] OFFICINAL. _Juniperus sabina_ from Central and South of Europe (the young branches yield an essential oil). The wood of _J. communis_ is used in the production of an essential oil, and _J. oxycedrus_ in the production of empyreumatic oil. The “berry-cone” of _J. communis_ is officinal, and is also used for gin.--The wood of _J. virginiana_ (N. Am.) is known as red cedar, and is used for lead-pencils. Sandarack resin is obtained from _Callitris quadrivalvis_ (N.W. Africa). THE FOLLOWING ARE CULTIVATED IN GARDENS:--_Thuja occidentalis_ (Arbor vitæ) (N. Am.), and _orientalis_ (China, Japan); _Juniperus sabina_ and _virginiana_; _Thujopsis dolabrata_ (Japan); _Cupressus lawsoniana_ (California), _C. sempervirens_ (S. Eur., W. Asia), and other species, are grown especially in conservatories, and in Southern Europe particularly in cemeteries.--The _Retinospora_ species which are so often planted, do not belong to an independent genus, but are obtained from cuttings, taken from seedling-plants with acicular leaves (see page 267). Class III. =Gneteæ.= This class, independent of extinct forms, comprises the most highly developed of the Gymnosperms, partly from the circumstance that a perianth of 2–4 members encloses the _terminally placed ovule_, which is provided with one, or (in _Gnetum_) two, integuments, and partly owing to the fact that the wood has true vessels. There is only one order. [Illustration: FIG. 275.--_Welwitschia mirabilis_ (considerably reduced). The horizontal lines indicate the surface of the soil.]