Wood and stem anatomy of Sarcobatus (Caryophyllales):: systematic and ecological implications

Quantitative and qualitative data are given for Sarcobatus vermiculatus (Hook.) Torr. stem anatomy in order to provide information relevant to Behnke's segregation of Sarcobatus from Chenopodiaceae and his idea that Sarcobataceae belong in suborder Phytolaccineae rather than suborder Chenopodiaceae. Sarcobatus has highly xeromorphic wood such as in xeric Chenopodiaceae (presence of vasicentric tracheids, narrow vessels, short vessel elements, numerous vessels per group, helical sculpturing of vessel walls), but these features could have evolved independently in both suborders. Nonbordered perforation plates, present in Sarcobatus, are widespread in Caryophyllales s.str. and may prove to be a defining feature for the recently expanded Caryophyllales together with the neighbouring order Santalales. A single-layered lateral meristem occurs in genera of Chenopodinae with successive cambia, but also in genera of Phytolaccineae. Likewise, raylessness occurs in both suborders. Stem and wood anatomy does not provide decisive evidence for placement of Sarcobatus in Phytolaccineae, but it does not provide any evidence against that treatment.