602 



BOTANY 



PART II 



cone, which till then have been closely pressed together. The cones subsequently 

 are shed. Pinus montana, a dwarf Pine occurring on mountains ; P. pinea, P. 



cembra, Avith edible seeds ; P. laricio, Corsican 

 Pine from Austria ; P. Pinaster, Maritime Pine 

 from the Mediterranean region ; P. taecla, P. 

 Strobus, Weymouth Pine, P. Lambertiana from 

 N". America. 



POISONOUS. Jtmipents Sabina, Taxus baccata. 

 OFFICIAL. Juniperus oxycedrus and other 

 species yield OLEUM CADINUM ; Juniperus com- 

 munis, OLEUM JUNIPERI ; Abies balsamea sup- 

 plies TEREBINTH i NA CANADENSis ; Abies siUrica 

 supplies OLEUM PINI SIBIRICAE ; Pinus sylvestris 

 and other species produce OLEUM TEIIEBINTHINAE 

 and RESINA ; P. sylvcslris, etc., PIX LIQUIDA ; 

 unofficial products are obtained from other species 

 of Pinus. 



Order 4. Gnetinae 



The only Family in this order is that of the 

 Gnetaceae, to which only three genera belong : 

 FIG. 594. Ephedra altissima. 1, Habit Ephedra (Fig. 594), leafless shrubs of warm dry 



of a male inflorescence. .?, An 

 inflorescence with unripe fruits. 

 ( nat. 



regions of the northern hemisphere ; IVelwitschia 

 mirabilis (Fig. 595), a monotypic plant from 

 the deserts of South-West Africa ; the widely 

 expanded summit of the stem bears after the cotyledons only a single pair of 

 leaves, which are 1 m. in length and continue to grow at their bases ; Gnctum 

 (Fig. 597), tropical trees or climbers with broad, reticulately-veined leaves. These 



Fig. 595. Welwitscliia mirabilis. Young plant (from EXCJLER and PRANTL). 



genera, while differing widely in appearance, agree in possessing opposite leaves 

 (in Ephedra reduced to scales), in the development of vessels in the secondary 

 wood, the absence of resin canals, and in the presence of a perianth to the flowers, 

 which are usually dioecious (Fig. 596). 



These points of agreement with both Gymnosperms and Angiosperms make 

 the group in many ways an intermediate one between the two classes. Insects 

 visit the flowers of all three genera, though they are as yet only known to effect 



