;So PHANEROGAMS. 



IV. TETRACYCLiE. 



Parts of the flower always arranged strictly in whorls ; the typical number of whorls 

 is four, the calyx, corolla, androecium, and gynaeceum each consisting of a single whorl ; 

 whorls generally pentamerous, rarely tetramerous (very rarely dimerous or octamerous) ; 

 any one of the whorls may be entirely wanting, or individual members may be abortive ; 

 this occurs most often with the stamens and carpels. Increase in number of the stamens 

 usually takes place by the interposition of one perfect or imperfect whorl between the 

 members of the typical whorl or a little outside it, or by doubling of the members, or by 

 branching of the original staminal leaves ; increase in number of the staminal whorls 

 themselves is rare. All the whorls usually alternate, but the stamens are not unfrequently 

 superposed on the petals. A tendency prevails in all the sections to a diminution of the 

 number of carpels below that of the members of the perianth-whorls ; very commonly 

 there are only two, one anterior and one posterior. Ovary almost always single and 

 polycarpellary, inferior or superior, unilocular or multilocular. 



I. Gamopetalse or Sympetalse. 



The petals united at the base into a tube or cup ; corolla never wanting. 



A. AnisocarpcE. The whorls or members of the whorls never larger than the 

 typical number ; calyx or some of the stamens sometimes abortive ; carpels usually 

 only two, one anterior and one posterior, or three and united into a single ovary •'. 



a. Hypogynse. 



Order 1. Tubiflorse. 



Families: i. Convolvulacea' (including Guscuteue), 



2. Polcmoniacese, 



3. Hydrophyllaceac, 



4. Borragineae, 



5. Solanaceae. 



Order 2. Labiatiflorse. 



Families: i. Scrophulariaceai, 



2. Bignoniaceae, 



3. Acanthaceae, 



4. Gesneraceae, 



5. Orobanchese, 



6. Ramondiea?, 



7. Selagineae, 



8. Globulariaceae, 



9. Plantagineae, 



10. Verbenaceae, 



1 1. Labiatae. 



Order 3. Diandrse. 



Families: i. Oleaceae, 



2. Jasminiaceae. 



Order 4. Contortae. 



Families: r. Gentianacea?, 



2. Loganiaceae, 



3. Strychnaceap, 



4. Apocynaceae, 



5. Asclepiadeae. 



^ The orders are arranged mainly after Braiin and Uanstein. 



