GNETACEJE. ^1"] 



(a) Juniperinetp. Fruit berry-like {Juniperiis, Sabiha). 



(b) Act'mostrcbe(v. Carpels united into valves ; afterwards separating as a four- or 



six-rayed star {Widdringtonia, Frenela, Actinostrobus^ Callttris, Libocedrus). 



(c) Thujopside(e. Carpels partially overlapping one another {Biota, Thuja, Thujopsis.) 



(d) Cupressinece vercB. Carpels peltate and polygonal in front (Cupressus, Ch^- 



moEcyparis). 



(e) Taxodineee. Carpels peltate or overlapping; leaves alternate (Taxodium Gly- 



ptojtrobus, Cryptomeria), 



Family 2. AbietineaB. Leaves usually acicular and arranged spirally, singly, or in 

 twos, threes, or rosettes on special short shoots ; flowers monoecious, rarely dioecious : 

 stamens numerous, with two or more long pollen-sacs ; female flower consisting of 

 a number of scale-like placentae arranged spirally, which are either themselves carpels or 

 are lignified outgrowths of small carpels ; micropyle of the ovule turned towards the base 

 of the placenta ; embryo with from two to fifteen cotyledons. 



(a) Abiet'meoB 'vera. Seeds in pairs on a scale-like placenta which springs from a 



small open carpellary leaf {Pinus, Abies, Tsuga, Larix, Cedrus). 



(b) Araucariece. Seed single on the carpel, and enveloped by it (Araucaria). 



(c) Cunninghamieee. Seeds single or numerous on a carpel [Dammara, Cunning- 



hamia, Arthrotaxis, Sequoia, Sciadopitys). 



Fam'ly 3. PodocarpeaB. Leaves acicular or broader, and arranged spirally ; flowers 

 monoecious or dioecious ; stamens short, with two roundish pollen-sacs ; female flower 

 consisting of an axis swollen above with small scale-leaves, from the axils of which (?) 

 the ovules spring ; embryo dicotyledonous. 

 Podocarpus {Dacrydium, Microcachrys). 



Family 4. TaxineaB. Leaves arranged spirally, acicular or often of considerable 

 breadth ; in Phyllocladus there are no foliage-leaves, these being replaced by leaf-like 

 branches ; flowers always dioecious ; stamens of various forms, bearing two, three, four, 

 or eight pendent pollen-sacs ; female flowers always consisting of a naked axis or 

 of one furnished with small leaves, bearing the erect ovules terminally or laterally ; 

 ripe seed enclosed in a fleshy aril or with the outer layer of the testa fleshy ; embryo 

 dicotyledonous. 



Phyllocladus, Salisburia, Cephalotaxus, Torreya, Taxus. 



C. GNETACE^^ 



This order includes three genera which differ strikingly in habit. The Ephedrae 

 are shrubs with no foliage-leaves and with long, slender, cylindrical green-barked 

 branches ; at the joints of the stem are two opposite minute leaves which grow 

 together into a bidentate sheath, and from their axils the lateral branches spring. 

 In Gnetum the leaves are also opposite on the jointed axes, but large and 

 stalked, with a broad lanceolate lamina and feather-veined venation. Thirdly, 

 Welwitschia mirahilis, so remarkable a plant in many other ways, possesses only two 

 foliage-leaves of immense size. They are extended on the ground and become 

 divided into strips as they become old ; the stem remains short, rising only slightly 



^ See Strasburger, Die Coniferen und Gnetaceen, Jena, 1872, 



