CONIFERALES 227 



natiirlichen Pflanzenfamilien (1889), but we have used the family 

 names. The number of species, indicated in parentheses, is taken 

 from Engler in Pflanzenfamilien. In the later Mesozoic the number 

 of species was much larger; in some genera, like Finns ^ at least two 

 or three times as large. The geographic distribution is much more 

 detailed in Engler's'^^ account. 



CONIFERALES 



The principal features of the six families, listed below, are as 

 follows : 



In the Abictaceae, the leaves and sporophylls are developed 

 spirally; the bract and ovuliferous scale are distinct; pollen grains 

 are winged; and leaves are of the needle type. 



The Taxodiaceae are also spiral, but the bract and ovuliferous 

 scale are almost completely united, and the pollen is wingless. 



In the Cupressaceae, the arrangement is cyclic and the strobili, in 

 most species, ripen fleshy. 



The Araucariaceae have the spiral arrangement; the bract and 

 ovuliferous scale are so thoroughly united that there is some doubt 

 whether the structure is double. The ovules are solitary and the 

 microsporangia hang from a peltate sporophyll. 



The Podocarpaceae have winged pollen and belong mostly to the 

 Southern Hemisphere. 



The Taxaceae have wingless pollen and belong mostly to the 

 Northern Hemisphere. 



I. ABIETACEAE 



1. Pinus (80-90), N. Hemisphere. S. Hemisphere only at Sunday Islands. 



2. Cedrus (4), Mediterranean region, W. Himalaya. 



3. Larix (10), N. Hemisphere. 



4. Pseudolarix (i), China. 



5. Picea (40), China, Japan, N. America, Central Asia, Europe. 



6. Tsuga (14), Asia from Himalaya to Japan and N. America. 



7. Pseudolsuga (7), Pacific, N. America and East Asia. 



8. Keeteleria (3), China. 



9. Abies (40), Middle and S. Europe, Central and temperate Asia, N. 

 America. 



II. TAXODIACEAE 



10. Sciadopilys (i), Japan. 



11. Sequoia (2), California. 



