| # Festuca of North America |

S.G. Aiken, M.J. Dallwitz, C.L. McJannet, and L.L. Consaul

### Festuca rigescens (Presl) Kunth

Rév. Gram. 1: Sup. 31. 1830. Diplanchne rigescens Presl, Rel. Haenk. 1: 260. 1830. Type: Peru. Haenk..

Notes. Hitchcock and Chase (1951) described this species as: densely tufted, about 30 cm tall; blades firm, involute, sharp-pointed; panicle narrow, few-flowered, 5 to 10 cm long; spikelets about 3-flowered, 6 to 7 mm long; lemmas ovate, thick convex, awnless to mucronate, 4 to 4.5 mm long. There is a single specimen of this species in the United States National Herbarium, labelled "Arizona, Tracy?". On the sheet is a note made by Professor Piper (Feb. 12, 1904) quoting Tracy, "In open pine woods 4 miles south-east of Flagstaff, about June 20 1887." This agrees exactly with specimens of this species from Peru, whence originally described. Since the species is not known north of Peru, except from this specimen, it seems probable that the label has been misplaced. The first author has not seen this specimen, but speculates from the description and the collection location, that it may be a specimen of F. calligera Rydb.

We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations with detailed captions, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa. See also Guidelines for using data taken from Web publications.

Cite this publication as: ‘Aiken, S.G., Dallwitz, M.J., McJannet, C.L. and Consaul, L.L. 1996 onwards. Festuca of North America: descriptions, illustrations, identification, and information retrieval. Version: 14th February 2019. delta-intkey.com’. Aiken, Dallwitz, McJannet, and Consaul (1997) should also be cited (see References).

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