Abstract Detail

Anatomy and Morphology

Pace, Marcelo [1], Hernandez-Hernandez, Brenda [2], Lohmann, Lucia [3], Angyalossy, Veronica [4], Cacho, N. Ivalu [5].

Wood and bark anatomical synapomorphies of  Bignoniaceae clades, with an emphasis in the taxonomic placement of Astianthus.

Wood and bark anatomical characters have been central to infer taxonomic affinities within Bignoniaceae since the mid 19th century. For example, the presence of variant secondary growth in tribe Bignonieae has been used to circumscribe this large tribe of lianas. In the past decades, new molecular phylogenetic data has consistently supported several morphological and anatomical features as synapomorphies of various Bignoniaceae clades. Some of these features were previously known from anatomical studies, such as the three wood anatomical types of Tabebuia s.l. matching perfectly three clades now recognized as three independent segregated genera, i.e., Handroanthus, Roseodendron and Tabebuia s.s. Likewise, differences in ray width and composition also represented synapomorphies of the Jacarandeae sections Monolobos, Dilobos, and Nematopogon. Other features were yet unknown, such as inter ray-vessel pits simple to semi-bordered and abundant tyloses, which emerged as synapomorphies of tribe Catalpeae. In this study, we: (1) summarize anatomical synapomorphies of various Bignoniaceae clades recovered using molecular phylogenetic data, and (2) use the enigmatic Mexican genus Asthianthus as an example to illustrate how wood and bark anatomy can help determine the phylogenetic placement of taxa whose taxonomic affinities remained unknown. Astianthus includes several morphological features that are unusual within Bignoniaceae such as simple, verticillate, and pulvinate leaves as well as a four-loculed ovary derived from the formation of a pseudo-septum. As a result, its phylogenetic position has remained unknown. Anatomically, Astianthus shares wood and bark traits with members of tribe Tecomeae s.s., namely the bark with scattered fibers, heterogeneous rays, and storied axial parenchyma. Our molecular phylogenetic studies recovered Astianthus within Tecomeae s.s., corroborating the affinities suggested by wood and anatomical traits.

1 - Universidad Nacional Autonoma de Mexico Instituto de Biologia, Botanica, Circuito Zona Deportiva sn de Ciudad Universitaria, Mexico City, DF, 04510, Mexico
2 - Institute of Biology, Botany, UNAM, Mexico City, 04510
3 - Universidade De Sao Paulo, Insituto De Biociencias, Departamento De Botanica, Rua Cojuba, 72 - Ap. 51, Sao Paulo, SP, 04533-040, Brazil
4 - Universidade De São Paulo, Botany, Rua Do Matao 277, Sao Paulo, SP, 05508-090, Brazil
5 - Institute of Biology, UNAM, Mexico City, 04510

wood anatomy

Presentation Type: Oral Paper
Session: AM1, Anatomy and Morphology
Location: Virtual/Virtual
Date: Wednesday, July 29th, 2020
Time: 1:30 PM
Number: AM1014
Abstract ID:493
Candidate for Awards:Katherine Esau Award,Maynard F. Moseley Award

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