Fig. 2.

Transverse light-microscope sections of woody Spermacoceae showing variation in vessel distribution, thickness of tracheids and scarcity of axial parenchyma. (A) Arcytophyllum setosum. (B) Spermacoce macrocephala. (C) Lathraeocarpa acicularis, thick-walled tracheids and vessels in the ground tissue. (D) Diodella sarmentosa, climbing species, wood cylinder partly broken up by large unlignified rays. (E) Nesohedyotis arborea, larger mean vessel diameter and lower vessel density than in most other woody Spermacoceae, axial parenchyma more common (arrows).