Wood Anatomy of Buddlejaceae

Sherwin Carlquist

doi:10.5642/aliso.19961501.05

Abstract

Quantitative and qualitative data are presented for 23 species of Buddleja and one species each of Emorya, Nuxia, and Peltanthera. Although crystal distribution is likely a systematic feature of some species of Buddleja, other wood features relate closely to ecology. Features correlated with xeromorphy in Buddleja include strongly marked growth rings (terminating with vascular tracheids), narrower mean vessel diameter, shorter vessel elements, greater vessel density, and helical thickenings in vessels. Old World species of Buddleja cannot be differentiated from New World species on the basis of wood features. Emorya wood is like that of xeromorphic species of Buddleja. Lateral wall vessel pits of Nuxia are small (2.5 ILm) compared to those of Buddleja (mostly 5-7 ILm) . Peltanthera wood features can also be found in Buddleja or Nuxia; Dickison's transfer of Sanango from Buddlejaceae to Gesneriaceae is justified. All wood features of Buddlejaceae can be found in families of subclass Asteridae such as Acanthaceae, Asteraceae, Lamiaceae, Myoporaceae, Scrophulariaceae, and Verbenaceae. Wood anatomy of Buddlejaceae relates to species ecology and size of wood sample, and is not useful in demonstrating that Buddlejaceae are closer to any particular one of these families; such evidence must be sought in molecular data and elsewhere.

Highlights

A survey of wood anatomy of Buddlejaceae was provided by Mennega (1980) as part of the Pflanzenfamilien monograph of Loganiaceae
Buddleja woods reflect sensitive adaptation to a diverse range of ecological sites, and the genus is an exemplary one in which to demonstrate the relationship between wood anatomy and ecology
In the Asteridae especially, woods often reflect rapid change with respect to ecology of species rather than other phyletic factors. This is notable, for example, in the huge family Asteraceae, where most of the diversity is interpretable in terms of ecology and habit, and relatively few patterns are attributable to systematic relationships (Carlquist 1966)

Summary

INTRODUCTION

A survey of wood anatomy of Buddlejaceae (as tribe Buddlejeae of Loganiaceae) was provided by Mennega (1980) as part of the Pflanzenfamilien monograph of Loganiaceae Her survey had the merit of providing descriptions of wood of the component genera, together with illustrations of wood sections by means of light microscopy. In these respects, Mennega's account represents an advance on the coverage of this group offered by Metcalfe and Chalk (1950). In the Asteridae especially, woods often reflect rapid change with respect to ecology of species rather than other phyletic factors This is notable, for example, in the huge family Asteraceae, where most of the diversity is interpretable in terms of ecology and habit, and relatively few patterns are attributable to systematic relationships (Carlquist 1966)

MATERIALS AND METHODS

CONCLUSIONS