400 THE SPERMATOPHYTES 





(sympetaly). The stamens are usually also borne on the same 

 outgrowth with the petals, so that they appear to arise from 

 them (epipetaly). The chief orders are: 



1. The ericad order, Ericales, containing the heath family, a 

 very characteristic group in the northerly parts of America, 

 Europe, and Asia, especially in the mountains. 



2. The gentian order, Gentianales, with more than 4000 

 species, including the gentians, olive family, milkweeds, etc. 



3. The phlox order, Polemoniales, with more than 14,500 spe- 

 cies, containing a number of prominent families, as the phloxes, 

 borrages, nightshades, figworts, mints, verbenas, and others. The 

 two-lipped flowers of the mints, figworts, etc., distinguish these 

 families among the Metachlamydece as the legumes are distin- 

 guished among the Archichlamydece, and the orchids among the 

 monocotyledons. 



4. The madder order, Rubiales, including the large madder 

 family, the honeysuckles, the valerian family, and the teasels. 



5. The bell wort order, Campanulales, containing the highest 

 of all angiosperm families, the Compositce, the largest in the 

 number of species (more than 12,000), and one of the most 

 successful groups of plants. 



SUMMAEY OF THE SPEKMATOPHYTES AND THEIE 

 ADVANCES OVER THE PTERIDOPHYTES 



374. Summary of the spermatophytes. The chief charac- 

 ters of the spermatophytes and their advances over the pteri- 

 dophytes are : 



1. The retention of the rnegaspore as an intimate part of the 

 megasporangium (nucellus) to become the embryo sac, and the 

 development of the female gametophyte parasitically within this 

 structure. The degeneration of the female gametophyte in the 

 angiosperms to a group of nuclei within the embryo sac. 



2. The origin of the ovule as a new structure from the mega- 

 sporangium (nucellus), together with enveloping integuments. 



