Verbena L., Glandularia Gmel., Junellia Moldenke, Lantana L. und Lippia L. (Verbenaceae) in Peru

The floristic revision of the following genera represented in Peru – Verbena, Glandularia,and Junellia as well as Lantana and Lippia, is presented. Understanding of generic and specific interrelationships has been in part contributed to by three collecting expeditions to Peru by the author. Novel characters have been surveyed and the taxonomic boundaries re-assessed in the light of this new information. Verbena, Glandularia and Junellia are closely related to each other, as are Lantana and Lippia. The first group has both herbaceous and woody members, varying between erect and creeping representatives. Their inflorescences are constructed of simple or branched spikes. The flowers have pentamerous fused calyces, with hypocrateriform, or sometimes cylindrical, five-lobed corollas. The ovary is bilocular, possessing an additional false septum forming four elongated nutlets. The second group has only woody members and, with one exception, are all erect. The inflorescence is a homeothetic pleiostachys with first order paraclades. The co-florescences are sited above a more or less long inhibition zone on the peduncle, their fertile zones producing dense arrangements of roughly spherical spikes. The ovary is also bilocular,but one locule is very much reduced. The genus Lantana produces a one- or two-seeded drupe, while Lippia develops two nutlets. The generic separation of the Verbena-Glandularia-Junellia group is problematic and has been the focus of much discussion in the literature. The three genera are retained mostly as they stand, based on the fruit structure and the seed morphology. In the later stages of seed development the basal part of the ovary is slender in Junellia and Verbena,and broad in Glandularia. Glandularia species also have bigger seeds than taxa in the two other genera. In Junellia the basal region of the style appears fused with the ovary tissue. In all Verbena species the calyx is, at maturity, not (or barely) longer than the nutlets, which are freely dehiscent, releasing the seeds. In the two other genera the calyx at maturity is distinctly longer than the nutlets and encloses them. Verbena has a basic chromosome number of x=7, Glandularia x=5, and Junellia x=10. To further clarify the intergeneric relationships of these three genera a molecular analysis is highly desirable. The separation of the individual species is based on the following characters that have shown themselves to be stable: habit, peduncle length and elongation at anthesis of the terminal inflorescence, bract shape and size, and flower form. Leaf shape, leaf size, and flower colour are have restricted value as species-defining characters because of their high variability. Additionally to these characters it is important in Glandularia species to note the lengthened gland-bearing anther connective, while seed form is significant in Junellia. The following species are represented in Peru: Verbena cajamarcensis, Verbena clavata, Verbena fasciculata, Verbena hispida, Verbena litoralis, Verbena parvula, Verbena pogostoma, Verbena pubescens, Verbena villifolia,Verbena weberbaueri,Glandularia cuneifolia, Glandularia laciniata, Glandularia microphylla, Glandularia tenuisecta,Junellia aspera, Junellia juniperina, Junellia minima. Two new species have been found and newly described: Verbena cajamarcensis and Verbena pubescens. Glandularia cuneifolia has been recombined from Verbena based on seed characters. It is recognised that Glandularia laciniata represents a number of different taxa. Although the main centre of distribution is indeed in Southern Peru, it was unfortunately not possible to come to any definitive conclusions concerning this taxon. The genera Lantana and Lippia exhibit very similar habits. They can be most easily and simply distinguished by their fruits. The fruits of Lantana are either leathery or fleshy drupes that, in contrast to Lippia, show a reduction from two to one well-developed locules, resulting in two one-seeded nutlets. Another good generic descriptor is the form of the calyx. All Lantana species have praemorse calyces with a fringed margin, while the peruvian species of Lippia have a (seemingly) two-lobed calyx. The anthers of Lippia flowers are inserted in the upper half of the corolla tube and reach the mouth of the tube. The anthers of Lantana flowers are instead basally inserted in the corolla tube. The co-florescences have, in Lantana a long, and in Lippia a very short or occasionally non-existent, inhibition zone. Lantana inflorescences always demonstrably elongate between anthesis and fruit maturity, a feature that never occurs in Lippia. And finally, Lippia has flowers which, at their largest, are only ever half as big as Lantana flowers. Lantana species can be distinguished easily using flower colour, the presence of fleshy or leathery drupes, the extent of co-florescence elongation after anthesis, and from the shape and size of the bracts. Lippia species are distinguished using characters including the degree of incision between the two lobes of the calyx, the presence of the extended anther connective and the shape and size of the bracts. The basic chromosome number for Lantana camara is x=11. The following Lantana and Lippia species are represented in Peru: Lantana angustibracteata, Lantana camara, Lantana cujabensis, Lantana radicans, Lantana reptans, Lantana rugulosa, Lantana scabiosaeflora, Lantana sprucei, Lantana tiliifolia, Lantana trifolia,Lippia alba, Lippia americana, Lippia antaica, Lippia ferruginea, Lippia tayacajana. Lantana radicans was found by Ruiz & Pavon and so labelled on the herbarium sheets, although the name was never validly published. This species is therefore newly described here. Among the studied herbarium material a single sheet of Lippia boliviana, labelled from Peru and collected by Haenke, was found. Haenke’s collection data, especially geographical entries, are known to be unreliable and, as this was not supported by any other material, it is assumed that this species only occurs in Bolivia.

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Ludwig-Maximilians-Universität

Year

2002

Author dc:creator

• Binder, Michaela

Repository record source_url

https://edoc.ub.uni-muenchen.de/1400/

OAI identifier oai:identifier

oai:edoc.ub.uni-muenchen.de:1400