Agrostis turrialbae Mez, Repert. Spec. Nov. Regni Veg. 18 (1-3): 4. 1922

Sylvester, Steven P., Cuta-Alarcon, Lia E., Bravo-Pedraza, William J. & Soreng, Robert J., 2020, Agrostis and Podagrostis (Agrostidinae, Poaceae) from paramos of Boyaca, Colombia: synoptic taxonomy including a key to Colombian species, PhytoKeys 151, pp. 107-160 : 107

Agrostis turrialbae Mez, Repert. Spec. Nov. Regni Veg. 18 (1-3): 4. 1922

= Agrostis arcta Swallen, Contr. U.S. Natl. Herb. 29 (9): 405. 1950. Type: Guatemala. Chimaltenango: moist roadside at Santa Elena, 2400-2700 m alt., 17 July 1933, A.F. Skutch 422 (holotype: US (US00131720)).

= Agrostis vesca Swallen, Contr. U.S. Natl. Herb. 29 (9): 405. 1950. Type: Guatemala. Chimaltenango: collected on open, moist roadside at Santa Elena, 2400-2700 m alt., 17 July 1933, A.F. Skutch 420 (holotype: US (US00131129)).

Type.

Costa Rica. Cartago: Volcán Turrialba, 27 May 1884, H. Pittier 855 (holotype: B; isotype: US (US00131127)).

Specimen examined.

Costa Rica. San Jose: Along Interamerican Highway ca 8.5 km E of road to La Cima, approximately 9°40'N, 83°51'W, 2600-2650 m alt., roadside and below highway, remnant evergreen forest, 30 July 1979, W.D. Stevens 13370 (MO2820979 [image!]).

Notes.

Described from páramos of Costa Rica, and mentioned by Pohl and Davidse (1994) to also occur in alpine pastures of Guatemala and Mexico, A. turrialbae has also been included in checklists for Colombia ( Giraldo-Cañas et al. 2016) and Venezuela ( Hokche et al. 2008). However, there is a lack of consensus on the identity of A. turrialbae and how to differentiate it from A. perennans s.l., with all type material of A. turrialbae and its synonyms out on loan at the time of writing this publication to help clarify this. The principal discrepancy refers to the form of the leaf blades, with the protologue and Pohl (1980) mentioning filiform flat or folded leaf blades, while Pohl and Davidse (1994) and Morales-Quirós (2003) state the blades to be involute and narrow, 0.2-1 mm in diameter as rolled, and rarely the cauline leaf blades being flat, and use this character to differentiate it from the usually flat bladed A. perennans . This may relate to the species A. arcta and A. vesca , described from Guatemala and considered synonyms of A. turrialbae by Pohl and Davidse (1994), with the protologues mentioning leaf blades being firm, folded and involute, curved, in A. arcta , or flat, filiform, or involute and straight in A. vesca . Agrostis perennans , in its broad sense, can also have involute or filiform leaf blades based on species currently considered synonyms of A. perennans , e.g. A. aberrans Steud., A. kufium Speg., A. tenuifolia M. Bieb. var. fretensis Hook. f., Vilfa elegans .

While all literature ( Pohl 1980; Pohl and Davidse 1994; Morales-Quirós 2003) also differentiates A. perennans from A. turrialbae by stating there is a lack of conspicuous basal foliage in the former, this may not be a good differentiating character as A. perennans usually has blades concentrated at the base of the plant when it is young, and only in subsequent flowering seasons it begins to elongate and lose its basal foliage. Pohl (1980) also mentions that paleas are minute in A. perennans , while in A. turrialbae paleas are absent, but this character appears to be too variable to be useful. Discrepancy in spikelet size is also apparent, with the A. turrialbae protologue stating 1.75 mm long and the A. vesca protologue stating 1.6-1.8 mm long, while all other publications describing the species ( Pohl 1980; Pohl and Davidse 1994; Morales-Quirós 2003) state 2-2.1 mm or 2-2.8 mm long.

We here tentatively differentiate the two species by A. turrialbae having leaf blades filiform, 0.2-1 mm wide when opened out, thin and flaccid, leaves mainly basal at maturity, and plants generally smaller with culms to 40 cm tall and panicles to 12 cm long and 6 cm wide (vs. leaf blades flat or conduplicate, (1-)1.5-6 mm wide when opened out, rarely involute in the basal leaves, usually thickened at the margins and keel, firm, leaves mainly basal early in the flowering season but tending to become mostly cauline with maturity, and plants generally larger, with culms to 100 cm tall and panicles often larger, to 22 cm long and 11 cm wide in A. perennans s.l.). No specimens of A. turrialbae that fit this delineation have been found at US from either Colombia or Venezuela. Furthermore, A. turrialbae may be better included among the broad A. perennans complex until a satisfactory revision can be done of this species complex, which has been found to comprise evolutionarily distinct lineages in unpublished molecular phylogenies (Konstantin Romaschenko, pers. communication).