no 



MORPHOLOGY OF THE ANGIOSPERMS 



center of the sporophyll — on tlie abaxial side in Degeneriaceae, An- 

 nonaceae, and Himantandraceae; on the adaxial side in Austrobaileya 

 and Magnolia (Fig. 50), and other primitive taxa. Stamens with semi- 

 laminar form occur in other primitive or fairly primitive families — Cera- 

 tophyllaceae, Lardizabalaceae, Eupomatiaceae, Lactoridaceae, Nym- 

 phaeaceae (Figs. 49B, C, E to H and 54F, H, I, J). In the specializa- 

 tion of tliis simple stamen, there has been reduction of the sterile tissues, 

 with retraction of the marginal areas. The lamina has been progressively 

 narrowed. The proximal part became the filament; the median section, 



rn 



U 



AUSTROBAILEYA 



HIMANTANDRA 



DEGENERIA 



MAGNOUA 



Fig. 50. Sketches of ranalian stamens showing variety of laminar types. Himan- 

 tandra and Degeneria, abaxial view; Austrobaileya and Magnolia, adaxial view. 

 A. maculatum, H. baccata, D. vitiensis, M. maingayi. {After Canright.) 



with the sporangia and the distal part, became the anther. In the anther, 

 the midvein region formed the connective and the sterile, distal part, the 

 appendage. 



The Anther 



The anther shows great variety in form and in its relation to the fila- 

 ment. Its morphological details are difficult to determine, so great has 

 been the reduction and so elaborate the form of the greatly reduced 

 types. In form, the anther ranges from linear to arrow-shaped, sub- 

 globose, and strongly four-angled. Typically, it is two-lobed, deeply so 

 in the more specialized types. The lobes are called anther lobes and 

 anther sacs. With lateral enlargement of the connective, the anther lobes 

 may be widely separated, and the lobes simulate anthers, as in the 

 Commelinaceae, Melastomaceae, and many Labiatae. The connective 



