[Botany • 2022] Paracephaelis aristata, P. pauciflora, P. grandifructa, P. russata, etc. (Rubiaceae: Pavetteae) • Monograph of the western Indian Ocean Genus Paracephaelis, with Description of Thirteen New Species

B. Paracephaelis pauciflora De Block sp. nov. 

C, G. P. saxatilis (Scott Elliot) De Block.

D. P. sericea (Arènes) De Block.

F. P. ranirisonii De Block sp. nov. 
H. P. tiliacea Baill.

J–K. P. capitulifera De Block sp. nov. 

L. P. russata De Block sp. nov.

in De Bloclk, 2022. 

DOI: 10.5852/ejt.2022.801.1685

ABSTRACT

The western Indian Ocean genus Paracephaelis is revised. Sixteen species are endemic to Madagascar, 12 of which are new for science: P. aristata sp. nov., P. bardotiae sp. nov., P. capitulifera sp. nov., P. gautieri sp. nov., P. grandifructa sp. nov., P. longipedicellata sp. nov., P. orientalis sp. nov., P. pauciflora sp. nov., P. ranirisonii sp. nov., P. russata sp. nov., P. sambavensis sp. nov., and P. seyrigii sp. nov. Paracephaelis trichantha occurs on the east coast of continental Africa and on the islands of the Aldabra Group. One other species is newly described from the Comoros, P. comorensis sp. nov. Paracephaelis is characterized by sessile inflorescences, pubescent inflorescence and flower parts, ovules arranged at the periphery of the placenta, laterally flattened seeds with entire endosperm and a shallow elongate hilum, and pollen with supratectal elements. Of the Malagasy endemics, five species are assessed as Critically Endangered with P. sambavensis sp. nov. possibly Extinct in the Wild, three are Endangered, four are Vulnerable, one is Near Threatened, and three are Least Concern. Outside Madagascar, P. trichantha and P. comorensis sp. nov. are assessed as Vulnerable.

Keywords: Aldabra, Comoros, East-Africa, Madagascar, taxonomy

Flowers, fruits and stipules of Paracephaelis Baill.
A–D.  Inflorescences. E–H. Fruits. I–J. Stipules. K–L. Infrutescences.
A, E, I. P. cinerea (A.Rich. ex DC.) De Block. B. P. pauciflora De Block sp. nov. C, G. P. saxatilis (Scott Elliot) De Block. D. P. sericea (Arènes) De Block. F. P. ranirisonii De Block sp. nov. H. P. tiliacea Baill. J–K. P. capitulifera De Block sp. nov. L. P. russata De Block sp. nov.

Photographs: P. De Block (B–E, G, I–L); S. Dessein (A, H); L. Gautier (F).

 

Petra De Block. 2022. Monograph of the western Indian Ocean Genus Paracephaelis (Rubiaceae – Pavetteae), with Description of Thirteen New Species. European Journal of Taxonomy. 801(1); 1–99. DOI: 10.5852/ejt.2022.801.1685