SPERMATOPHYTES 279 
ARCHICHLAMYDEAE 
This vast group contains a maze of forms whose relationships are very 
confusing. Over 61,000 species and 180 families are recognized, which 
are grouped into 26 great alliances. Archichlamydeae include primi- 
tive angiosperms, and although they are prevailingly spiral, the cyclic 
condition, with a definite number in all of the floral members, is estab- 
lished in several of the higher alliances. It would be unprofitable to 
name all of the alliances, for many of them would suggest nothing to 
the elementary student. Some of the more significant will be selected 
for brief description, and the others grouped. 
i 12. (26 families, 5900 species.) This group of alliances is espe- 
cially puzzling as to relationships. They are regarded as relatively 
primitive forms, and include many of the most common trees, as 
willows, walnuts, beeches, oaks, etc. Many of them were formerly 
grouped as Amentiferae, a name referring to the characteristic flower 
cluster called ament or catkin, a cluster perhaps most familiar in the 
willows and alders. The flowers are naked or have a bractlike perianth, 
the floral numbers are generally indefinite, and wind pollination pre- 
vails. This assemblage does not seem to be related to any of the higher 
alliances. 
13, 14. (n families, 4070 species.) This is another apparently iso- 
lated group, including such plants as smartweed (Polygonum), pigweed 
(Amaranthus and Cheno podium), pinks (Caryophyllaceae), etc. In 
structure the flowers range from a bractlike perianth to distinct sepals 
and petals, and are mostly cyclic, three, four, and five being the pre- 
vailing floral numbers. Insect pollination is established only among 
the pinks. 
15. Ranales (16 families, 4050 species). This is recognized as the 
great genetic alliance, which means that the higher alliances are thought 
to have been derived from it. Familiar families are the crowfoots or 
buttercups (Ranunculaceae), the water lilies (Nymphaeaceae), and the 
magnolias (Magnoliaceae). There is a distinct calyx and corolla; the 
flowers are hypogynous; and the numerous carpels form separate pistils- 
(apocarpous). Although the cyclic number is often evident in the 
calyx and corolla, the stamens and carpels at least usually retain the . 
spiral condition and are indefinitely numerous. By some it is thought 
that the Ranales are the most primitive Archichlamydeae, not only 
giving rise to the other dicotyledons, but also to the monocotyledons. 
