Wednesday, June 5, 2024

[Botany • 2024] Praxelis cleggiae (Asteraceae: Eupatorieae: Praxeliinae) • A New Species from the Granite Inselbergs in the east of the Departamento de Santa Cruz, Bolivia


Praxelis cleggiae D.J.N.Hind & S.L.Edwards,

in Hind et Edwards, 2024.
 
Summary
Praxelis cleggiae (Compositae: Eupatorieae: Praxeliinae) is described and illustrated from the granite inselbergs (upon which it is most common), and on road crown chippings on old roads, in the Departamento de Santa Cruz, Bolivia; it has a disjunct distribution and is also found on the Serranía San Simón, in the San Ignacio Schist belt, Departamento de Beni. Material of this species was mostly determined as P. insignis (Malme) R.M.King & H.Rob., a Brazilian species, described from the metamorphosed sandstone of what is now the Parque Nacional da Chapada dos Guimarães in Mato Grosso State. The two species have some superficial resemblance, but differ significantly in plant size, internode length (relative to leaf length), branching, leaf shape and size, phyllaries, achenes and pappus. The total number of species of Praxelis recognised in Bolivia is now seven, and 20 species in the genus worldwide. 

Key Words: Asteraceae, ChromolaenaEupatoriopsis, Island-like Systems, Praxeliopsis


Praxelis cleggiae. A rootstock; B prostrate stem portion with axillary clusters/tufts of leaves; C upper part of flowering stem; D apical part of flowering stem bearing one old capitulum, post-dehiscence of phyllaries and achenes, showing just the conical receptacle; E leaves; F capitulum; G l.s. capitulum; H middle phyllary apex — l.h. showing abaxial view, r.h. showing adaxial view; J innermost phyllary; K detail showing surface of receptacle; L floret; M detail of corolla lobe apex (l.h. view of adaxial surface, r.h. view of abaxial surface); N corolla opened out showing position of anther cylinder; P style and style arms; Q achene (obcompressed) in lateral view showing asymmetric carpopodium facing right (towards attachment point on receptacle); R base of achene showing adaxial surface and carpopodium; S detail of setula from achene body; T detail of apex of pappus seta.
 A, C, D, F – T from Wood et al. 24182 (holotype in K); B & E from Wood et al. 13202 (K). 
Drawn by Naoko Yasue.


Praxelis cleggiae D.J.N.Hind & S.L.Edwards, sp. nov.

RECOGNITION. Praxelis cleggiae is similar to P. insignis in that both species are procumbent and spreading, commonly have a single capitulum per inflorescence (if terminal) or inflorescence branch, and possess inconspicuously bracteolate pedicels. Praxelis cleggiae is distinguished from P. insignis in possessing markedly longer internodes (c. 2 – 9 cm vs c. 0.3 – 0.8 cm), with leaves scarcely longer than internode (vs leaves c. 3 – 6+ times longer than ...

ETYMOLOGY. The species is named after Rosemary (Rosie) Clegg, formerly TIPAs Bolivia Co-ordinator, at RBG, Kew, now a post graduate student being co-supervised by the first author of this paper. Rosie first brought the issue of this species to the attention of the first author when she began assessing the species for Red Data listing, at which point a critical assessment was made of the material.

 
D. J. Nicholas Hind and Sara L. Edwards. 2024. Praxelis cleggiae (Compositae: Eupatorieae: Praxeliinae), A New Species from the Granite Inselbergs in the east of the Departamento de Santa Cruz, Bolivia.  Kew Bulletin. DOI: s12225-024-10189-1