430 MORPHOLOGY OF THE ANGIOSPERMS 



Eupteleaceae, Cercidiphyllaceae, Illiciaceae, Schisandraceae, Annona- 

 ceae, Ranunculaceae, Beiberidaceae, Lardizabalaceae, 



Secretory cells of the "ethereal oil" type are characteristic of many 

 ranalian families and probably represent structure inherited from a 

 common ancestral stock. They are present in the Winteraceae, 

 Degeneriaceae, Eupomatiaceae, Himantandraceae, Magnoliaceae, An- 

 nonaceae, Myristicaceae, Monimiaceae, Gomortegaceae, Hernandiaceae, 

 Lauraceae. The oil cells, when abundant, give an aromatic character to 

 all parts of the plant. (They are present also in the Piperales.) 



The primitive nodal structure, unilacunar with two traces, is present 

 in the Austrobaileyaceae, Amborellaceae, Monimiaceae, Lactoridaceae, 

 Illiciaceae, Schisandraceae, Chloranthaceae, Lauraceae, Calycanthaceae. 

 The derived, trilacunar node and its modifications characterize the 

 remaining families. 



Two groups of families that seem closely related are the magnolian 

 line — the Magnoliaceae, Annonaceae, Schisandraceae, Illiciaceae with 

 perhaps the Eupomatiaceae, Degeneriaceae, and Himantandraceae — 

 and the lauralian line — Hernandiaceae, Myristicaceae, Monimiaceae, 

 Gomortegaceae, Lauraceae, with perhaps the Berberidaceae. The mag- 

 nolian line is held together by large, spirally built, polymerous flowers 

 with well-developed perianth, laminar stamens, and tri- or multilacunar 

 nodes. The Degeneriaceae, Himantandraceae, and Eupomatiaceae have 

 been called a "fairly natural group," allied to the Magnoliaceae. The 

 lauralian families have in common unusual androecial structure, closely 

 similar wood structure, and unilacunar nodes. The stamens are nectary- 

 bearing (the Myristicaceae and some of the Monimiaceae lack the 

 nectaries), borne in small fascicles, and have distinctive valvular de- 

 hiscence. 



Isolated among the Ranales are the Cercidiphyllaceae, Cerotophtjlhim, 

 Tetracentraceae, Trochodendraceae, Eupteleaceae, and Austrobaileya- 

 ceae. The Winteraceae also stand apart from all other families, with 

 the possible exception of the Lactoridaceae. The Calycanthaceae show 

 resemblances to the Magnoliaceae in perianth and cortical vascular 

 system and to the Eupomatiaceae in pollen type and in remarkable 

 adaptation to beetle pollination. But staminodes are abundant in 

 Eiipomatia and Cahjconthiis and absent in the Magnoliaceae. The 

 presence of staminodes above the stamens in Eiipomaim and above and 

 below in Himanfandra seems to bring these two genera together, but 

 places them far from the magnolian line. The staminodes are below in 

 Cali/canthtis. 



The Myristicaeae, Eupomatiaceae, and Annonaceae have ruminate 

 endosperm, a character claimed to tie these families together, but the 



