CONIFERALES (TAXACEAE) 319 



2. The spore-producing members 



The strobili of Taxaceae are monosporangiate, and in the main 

 the j)lants are dioecious, Saxegothaea, some species of Podocarpus, 

 and perhaps occasionally Phyllodadus being monoecious. The 

 interesting observation has been made (149) that in a specimen of 

 Saxegothaea growing in a greenhouse at Uppsala, some of the branches 

 are mostly staminate and others mostly ovulate. No bisporangiate 

 strobili have been reported, except a single case of Phyllodadus 

 alpina (115), in which an ovule was found at the base of a staminate 

 strobilus. Although the statement is current that usually strobili 

 are not formed among the Taxaceae, this refers to the ovulate strobili, 

 for the microsporophylls are as definitely organized into simple strobili 

 as are those of Pinaceae. Even in the case of the ovulate strobili, 

 the statement must be taken with a good deal of allowance, for such 

 strobili do occur, as in Microcachrys and Saxegothaea, but not always 

 in the same conspicuous way as among the Pinaceae. 



THE MICROSPORANGIUM 



The staminate strobili are borne on short stalks in the axils of foliage 

 leaves (scales in Phyllodadus) , usually appearing upon young shoots 

 of the same season (fig. 375). The relations of leaves and strobili 

 are such that if the axis of the shoot were shortened, becoming a dwarf 

 shoot, it would be transformed into a compound strobilus; as it is, 

 the staminiferous shoot often resembles a raceme (150). The 

 strobili are generally solitary in the axils, but they may occur in pairs 

 or in threes, as in Podocarpus (139) and Saxegothaea (150); and in 

 Phyllodadus they are borne in clusters of two to eight at the tips of 

 the lateral branches. In the monoecious Saxegothaea the ovulate 

 strobilus is terminal on the short branch in the axils of whose leaves 

 the staminate strobili are borne. The size and form of the strobili 

 are variable, ranging from 2 to 20 mm. in length, and in form from 

 linear to nearly spherical. The strobili consist externally of a variable 

 number of overlapping sterile bracts, which sometimes completely 

 envelop the tip, as in Torreya (loi), and sometimes form an involucre- 

 like cluster at the base of the strobilus, as in Saxegothaea (150). 



The sterile bracts (sporophylls) are replaced above by a more or 

 less indefinite number of stamens. Among the taxads, disregarding 



