Abstract Detail


Gerrits, Julie [1], Tyrrell, Christopher [2].

Morphological analysis of Arthrostylidium pubescens (Poaceae: Bambusoideae: Bambuseae: Arthrostylidiinae) for species delineation.

Arthrostylidium (Poaceae: Bambusoideae: Bambuseae: Arthrostylidiinae), a genus of neotropical woody bamboos containing 31 described species, is under-researched taxonomically. Arthrostylidium pubescens Rupr., one of the oldest species in the genus, overlaps morphologically and geographically with other species of Arthrostylidium, making it difficult to distinguish A. pubescens from its congeners. Historical descriptions provide insufficient detail for a full circumscription of this species, suggesting that herbarium specimens of this species are possibly misidentified. We measured or assessed 31 quantitative and qualitative characters of each specimen from each of 108 herbarium specimens. We then used univariate and multivariate analyses to compare A. pubescens with other species of Arthrostylidium to evaluate species-defining morphological characteristics. Based on hierarchical clustering, our data suggest that only about 20% of all specimens labeled as A. pubescens are morphologically similar to the type specimen for this species. The most discriminating characteristics are: foliage leaf length, foliage leaf width, spikelet length, leaf shape, leaf base, fimbriae length, fimbriae color, fimbriae incidence, adaxial leaf vestiture, abaxial leaf vestiture and floret position. The divergence in morphology from the type specimen observed in 80% of A. pubescens specimen highlights the need for a molecular phylogenetic analysis of Arthrostylidium. Further investigation into morphology and phylogenetics of this genus may reveal taxonomic changes or even novel taxa.  

1 - Oberlin College, Department of Biology, 119 Woodland St., Oberlin, OH, 44074, USA
2 - Milwaukee Public Museum, Botany Department, 800 W Wells St, Milwaukee Public Museum, Milwaukee, WI, 53233, United States


Presentation Type: Poster
Session: P, Systematics Posters
Location: Virtual/Virtual
Date: Thursday, July 30th, 2020
Time: 5:00 PM Time and date to be determined
Number: PSY007
Abstract ID:294
Candidate for Awards:None

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