108 GNETACE^C. Ephedra. 



SUBCLASS II. GYMNOSPERM^E. 



Ovules (always orthotropous) naked upon the surface of a scale or bract or within 

 a more or less open perianth, fertilized by the direct contact of the pollen with the 

 nucleus. Flowers monoecious or dioecious. Cotyledons 2, or often several in a 

 whorl. Wood composed mainly of disk-bearing tissue without proper vessels. 



ORDER CI. GNETACE^ffiJ. 



Shrubs or small trees of very various habit, mostly with jointed opposite or fas- 

 cicled branches and foliaceous or scale-like opposite (or ternate) exstipulate leaves, 

 the flowers mostly dicecious, with decussate persistent bracts ; the staminate in 

 aments, with solitary or monadelphous stamens within a membranous bifid calyx- 

 like perianth, the anther-cells (1 or 2) dehiscent by a pore or chink at the apex : 

 fertile flowers of an erect sessile ovule, with simple integument (separating above 

 into two) terminated by an exserted style-like process (micropyle), included within 

 an urceolate perianth which becomes hardened and often thickened in fruit. 

 Embryo axile in fleshy albumen, with superior radicle and two short cotyledons. 



An order intermediate between the coniferous and the angiospermous orders, being allied on 

 the one side to the Taxatece and on the other to the Lormdlwcece, etc. It contains only two gen- 

 era besides Ephedra; viz., Gnetum, of a dozen or more species native to tropical Asia and America, 

 with broad petiolate leaves, verticillate flowers, and often drupaceous fruit with double integu- 

 ment, and Wclwitschia, a remarkable S. African genus of a single species, having a thick de- 

 pressed platform-like stem and only a single pair of very large permanent leaves. 



1. EPHEDRA, Tourn. 



Inflorescence dioecious, axillary ; aments small, of decussately imbricated oppo- 

 site or ternate and more or less connate bracts. Staminate flowers solitary at the base 

 of each bract, with compressed 2-lobed membranous perianth, and the 3 to 8 fila- 

 ments united into a clavate stamineal column. Anthers 2-celled, rounded or sub- 

 cuneate. Fruiting aments with all the lower bracts empty, the flowers (1 to 3) 

 sessile at the apex. Perianth coriaceous, hardening in fruit, 3 4-angled, perforated 

 only for the passage of the micropyle. Ovule solitary ; rnicropyle slender, entire. 

 Seed with thin testa. Shrubs with numerous equisetum-like branches, the leaves 

 reduced to sheathing (at length distinct) scales, persistent or deciduous. 



A genus of about 20 species, in the warmer temperate regions or mountains of the tropics, 

 chiefly in desert or alkaline localities. Half of the species belong to the Old World ; the rest, 

 with the exception of the following, are South American. Our species have the aments solitary 

 or few in the axils, and the scales, branches and bracts sometimes ternate the last character 

 being exceptional in the genus and order. Of little value except for their well known medicinal 

 virtues, respecting which see Rothrock in Wheeler's Eep. vi. 50. 



* Scales 2-lobed and branches (not spinose) opposite : bracts opposite and evi- 

 dently connate, scarious only on the margin: fruit smooth, solitary or in 

 pairs. 



1. E. Nevadensis, Watson. An erect shrub, 2 feet high or more, with erect 

 or spreading usually somewhat scabrous branches : scales (1 to 3 lines long) sheath- 

 ing, with short blunt lobes or with more or less elongated tips, at length mostly 

 deciduous : staminate aments sessile or rarely shortly pedunculate, ovate, of 4 to 6 

 pairs of bracts ; the 4 to 8 anthers usually closely sessile upon the exserted stamineal 



