¤ A big thank to the Royal Horticultural Society for allowing me to use its descriptions.
Thanks to Pam Hayward and to David Chamberlain.

¤ Thanks to Jens Birck (Denmark), Chris Callard (U.K.), Frédéric Danet (France), Don Hyatt (U.S.A.), John McQuire (U.K.), Graham Smith (New-Zealand), and Garth Wedemire (Canada) too for having sent me pictures in order to illustrate my cards.

There are two ways you can use for this classification according your knowledges :

1)  the alphabetical list : in putting your mouse above a letter you open a list of species which the name begins by this letter. Use the wheel of your mouse or the scroll box to move up or down the list.   Then to open a card click on its name.

2)  the classification : in clicking successively on the different sections and subsections of the classification in order to find the species you want to see the card.   To open its card click on it.

All cards contain the description of the subgenus, of the section or of the subsection which the species belongs to and the names of the other species which make it up. If you put your mouse over some technical words a window will open with a picture or a drawing. That makes easier to realize the common features of a section or a subsection in examining the pictures of the other members.