LINNEAN SYSTEM. 187 
661. In the 19th class, Syngenesia, there are 5 orders* : 
1. Polygamia AEqualis. Here all the bee 
florets are hermaphrodite or perfect, { Leontodon Taraxacum, 
each having stamens, and an ovary ( Dandelion. 
SR AI gdh = Sob cicconnmnasnaursigss 
2. Polygamia Superflua. Here the 
florets of the disk (378) are provid- 
ed with stamens and _ pistil, while 
those of the ray (378) have only a 
pistil, both bearing seed,.............0« 
Tanacetum vulgare, 
Tansy. 
3. Polygamia Frustranea. Were the 
florets of the disk have both stamens 
_ and pistil, while those of the ray 
have neither stamens nor pistil, or 
_ an abortive pistil (neuter),............ 
Centaurea benedicta, 
Blessed Thistle. 
4, Polygamia Necessaria. Here the Saar 
florets of the disk have only stamens, \ serine nic ysetince 
~ those of the ray only pistils,..... ..... Z 
5. Polygamia Segregata. In this or- 
_ der the common calyx or involucre 
_ encloses several smaller calices or }- Echinops, Globe Thistle. 
_ cups, which separate and surround 
the florets, 
; 662. In the 20th, 21st, and 22d classes, Gynandria, Mo- — 
heecia, and Dicecia, the orders are founded on the characters — 
of several of the preceding classes, generally on the number 
ofthe stamens. 
663. In the 23d class, Polygamia, there are 3 orders : 
1. Monecia, in which one plant may ay - 
have perfect flowers and male anes 
flowers, perfect flowers and female + Veratrum album, White a 
flowers, or perfect, male, and female Hellebore. ae 
Eyes ss sasorcnccyea eee : 
ry . Ono eee ewe wee eens 
2. egg in which the several kinds of flowers are found on 2 
ts. ee ee 
_* Linneus had a sixth order, Monogamia, incl ding plants with united an-— 
thers, but simple flowers, now generally placed in Pentandria, having ‘Bete 
affinity with the Syngenesia. aoe ecee ee 
