Thorneochloa diegoensis (Swallen) Romasch., comb. nov.,

Peterson, Paul M., Romaschenko, Konstantin, Soreng, Robert J. & Reyna, Jesus Valdes, 2019, A key to the North American genera of Stipeae (Poaceae, Pooideae) with descriptions and taxonomic names for species of Eriocoma, Neotrinia, Oloptum, and five new genera: Barkworthia, x Eriosel, PhytoKeys 126, pp. 89-125: 105-109

publication ID

http://dx.doi.org/10.3897/phytokeys.126.34096

persistent identifier

http://treatment.plazi.org/id/D8D26043-C2A9-756D-EB54-5E2D286632EF

treatment provided by

PhytoKeys by Pensoft

scientific name

Thorneochloa diegoensis (Swallen) Romasch., comb. nov.
status

 

Thorneochloa diegoensis (Swallen) Romasch., comb. nov. 

Stipa diegoensis  Swallen, J. Wash. Acad. Sci. 30(5): 212, f. 2. 1940 [Basionym] ≡ Achnatherum diegoense  (Swallen) Barkworth, Phytologia 74(1): 7. 1993. Type: USA, California, San Diego Co., Proctor Valley near Jamul, along vernal stream in chaparral, 23 May 1938, F. F. Gander 5778 (holotype: US-1761177!; isotypes: AHUC-30095 [image!], CAS-0005662 [image!], DAO-000465418 [image!], F-0044439F [image!], SD-00000072 [image!]). Fig. 5 A–EView Figure 5.

Distribution and habitat.

Thorneochloa diegoensis  is found in Channel Islands (Santa Barbara County), San Diego, and Ventura Counties and Baja California, Mexico in rocky soil along vernal streams and canyons in chaparral and coastal sage-scrub vegetation; usually below 500 m ( Barkworth 2007; Calflora 2018).

Comments.

Molecular sequence analysis reveals multiple origins of this taxon. In our preliminary ITS-derived phylogenetic tree Thorneochloa diegoensis  aligns within Nassella  whereas in the combined plastid-derived tree it aligns within Pseudoeriocoma  ( Valdés Reyna et al. 2013). Geographically, the most likely parents, if of hybrid origin, would be Nassella mucronata  (Kunth) R.W. Pohl and Pseudoeriocoma eminens  . A more detailed genetic study using low-copy nuclear genes would perhaps resolve this hypothesis.

A key to the native and introduced (marked with an asterisk) genera of Stipeae  (and Ampelodesmeae) in North America (modified from Barkworth 2007)

Excluded name

Kingdom

Plantae

Phylum

Tracheophyta

Class

Liliopsida

Order

Poales

Family

Poaceae

Genus

Thorneochloa

Loc

Thorneochloa diegoensis (Swallen) Romasch., comb. nov.

Peterson, Paul M., Romaschenko, Konstantin, Soreng, Robert J. & Reyna, Jesus Valdes 2019
2019
Loc

Achnatherum diegoense

Barkworth 1993
1993
Loc

Stipa diegoensis

Swallen 1940
1940