New combinations and updated descriptions in Podagrostis (Agrostidinae, Poaceae) from the Neotropics and Mexico
Author
Sylvester, Steven P.
College of Biology and the Environment, Nanjing Forestry University, Long Pan Road No. 159, Nanjing, 210037, China & Royal Botanic Gardens, Kew, Richmond, Surrey, TW 9 3 AE, UK
https://orcid.org/0000-0001-5577-8782
steven_sylvester@hotmail.com
Author
Peterson, Paul M.
Department of Botany, National Museum of Natural History, Smithsonian Institution, Washington DC 20560, USA
Author
Romaschenko, Konstantin
Department of Botany, National Museum of Natural History, Smithsonian Institution, Washington DC 20560, USA
Author
Bravo-Pedraza, William J.
Grupo Sistematica Biologica, Herbario UPTC, Escuela de Biologia, Facultad de Ciencias, Universidad Pedagogica y Tecnologica de Colombia, Avenida Central del Norte 39 - 115, Tunja-Boyaca, Colombia
Author
Cuta-Alarcon, Lia E.
Grupo Sistematica Biologica, Herbario UPTC, Escuela de Biologia, Facultad de Ciencias, Universidad Pedagogica y Tecnologica de Colombia, Avenida Central del Norte 39 - 115, Tunja-Boyaca, Colombia
Author
Soreng, Robert J.
Department of Botany, National Museum of Natural History, Smithsonian Institution, Washington DC 20560, USA
https://orcid.org/0000-0002-8358-4915
text
PhytoKeys
2020
148
21
50
http://dx.doi.org/10.3897/phytokeys.148.50042
journal article
http://dx.doi.org/10.3897/phytokeys.148.50042
1314-2003-148-21
6E288E0A8F725B2787799DD17F2B1642
Podagrostis trichodes (Kunth) Sylvester & Soreng
comb. nov.
Fig. 5
Aira trichodes
(Kunth) Spreng., Syst. Veg. [Sprengel]) 1: 276. 1825[1824].
Agrostis trichodes
(Kunth) Roem. & Schult., Systema Vegetabilium 2: 361. 1817.
Vilfa trichodes
Kunth, Nova Genera et Species Plantarum (quarto ed.) 1: 139. 1815[1816].
=
Agrostis bogotensis
Hack., Repert. Nov. Sp. Fedde 8: 518. 1910. Type: Colombia. S. Cristobal prope Bogota [
pres
de Bogota], [2500-3000 m alt.], 13 July 1908,
F. Apolliniaire
s.n. (holotype: W (W19160027256 [image!]); isotypes: BM (BM000938528 [image!]), MPU (MPU027104 [image!]), SI (SI000495 [image!] fragm. ex US), US (US75365 fragm. [not seen])).
Type.
Peru. Crescit in crepidinibus Andium Peruvianum justa Montan, Santa Cruz et Guambos, alt. 1350 hexap. [2469 m alt.], floret Augusto,
F.W.H.A. Humboldt & A.J.A. Bonpland s.n.
(
holotype
: P [not seen];
isotypes
: HAL (HAL0106929 [image!]), US (US75364! fragm. ex P)).
Figure 5.
Podagrostis trichodes
.
A
Whole plant
B
spikelets, with the floret detached and raised above the glumes so that the rachilla prolongation (indicated with a red arrow) can be seen
C
section of inflorescence
D
leaf blade, showing abaxial surface.
A, B
images of specimen L.E. Cuta-Alarcon 362 (FMB)
C, D
images of specimen M.C. Gomez 1 (US3534984).
Description.
Tufted perennial
forming short dense tufts, with the basal mats reaching c. 4-11 cm tall and inflorescences well-exserted from the basal foliage.
Tillers
intravaginal.
Culms
7-20(-30) cm tall, erect, simple, delicate;
nodes and internodes
terete, smooth, nodes usually hidden in the sheaths with 0(-1) nodes exposed at flowering, uppermost internode usually <1 cm long, usually not longer than the sheath.
Leaves
generally basal;
sheaths
terete, glabrous, finely to densely scabrous; flag sheath 2-5.6 cm long; basal sheaths 0.7-1.5 cm long, striate, becoming fibrous;
ligules
0.7-1.7(-2.5) mm long, membranaceous, slightly to usually strongly decurrent with the sheath; flag ligules acute with a obtuse to truncate apex, usually slightly erose towards the apex; ligules of tillers 0.7-1.2 mm long, truncate;
blades
1-4 cm long, 0.3-0.4 mm wide in diameter, involute or convolute, acicular to capillaceous and filiform, usually curved, abaxial surface glabrous, finely to densely scabrous, adaxial surface glabrous, lightly to usually densely scabrous with prickle hairs usually short, less often long and robust.
Panicles
2-5(-6)
x
1-2(-3) cm, open, ovoid;
panicle branches
ascendant to patent, branched above the middle, filiform, with spikelets not present near the base, smooth to usually scaberulous, longest branches 0.8-3 cm long;
pedicels
1-2 mm long, usually longer than the length of the spikelets, divaricate, smooth to usually lightly scabrous.
Spikelets
1-1.5 mm long;
glumes
remaining on the inflorescence at maturity or one or both readily caducous at maturity and falling before the floret, equal or subequal, the lower often slightly longer than the upper or less often vice versa, almost equaling the length of the floret or slightly longer, oblong-lanceolate, slightly to distinctly keeled, apex obtuse to acute, glabrous, keels scabrous just in the distal 1/3 to throughout their length, surfaces smooth a scabrous distally; lower glume 1-veined; upper glume 1- or 3-veined;
lemmas
1-1.5 mm long, glabrous, moderately to densely scabrous (
'smooth'
possibly mentioned by
Tovar 1993
!), sometimes granulose, faintly to strongly 5-veined, apex obtuse, awn lacking or to 0.5 mm long, straight, inserted medially or in the upper half of the lemma;
paleas
(0.7-)0.9-1.3 mm long, usually reaching from
3/4
to subequaling the lemma, less often reaching 2/3 the length of the lemma, keels obscure to fairly prominent, smooth, apex bifid and erose;
rachilla
absent or prolonged from the base of the floret (sometimes lacking in a small number of spikelets within the inflorescence), 0.2-0.5 mm long, glabrous, smooth to scabrous.
Calluses
0.05-0.1 mm long, slightly elongated or not, glabrous.
Flowers; lodicules
c. 0.4 mm long, lanceolate with acute apices, not lobed;
anthers
3 in number, 0.4-1 mm long.
Caryopses
c. 1 mm long, subterete, sulcus distinct, dark brown with apex dark; hilum 0.25 mm long, narrowly ovoid; endosperm solid. 2n = unknown.
Distribution and ecology.
Bolivia?, Colombia, Ecuador?, Peru, Venezuela, 2800-4500 m alt. Relatively humid high-Andean puna grasslands of southern and central Peru and
paramo
grasslands of Ecuador, Colombia and Venezuela.
Tovar (1993)
mentions that the species may also occur in Bolivia, presumably in high-elevation cool and humid sites such as the Bolivian Yungas which have been referred to as
paramo
(
Garcia
and Beck 2006
), although no specimens have been verified by the authors. No specimens at the US herbarium were found from Ecuador after careful searching by the first author, although it is mentioned to occur there (
Hitchcock 1927
;
Tovar 1993
;
Jorgensen
and Ulloa-Ulloa 1994
;
Jorgensen
and
Leon-Yanez
1999
;
Luteyn 1999
). In Colombia, the taxon is known from multiple collections from
paramos
of the Cordillera Oriental of the Colombian Andes, belonging to Departamentos Cundinamarca,
Boyaca
, Santander, Santander Norte and Cesar. We present new regional records of the species for Departamentos Santander Norte and Cesar which are not mentioned in the recent checklist (
Giraldo-Canas
et al. 2016
).
Giraldo-Canas
et al. (2016)
also cite
Agrostis trichodes
for Departamento Meta, in the southernmost part of the Cordillera Oriental, and Departamento Magdalena, which contains
paramos
of the Sierra Nevada de Santa Marta, although no specimens have been verified. In Venezuela, the species is found in
paramos
of the Cordillera de Merida.
Usually found in frequently grazed areas where its short basal tufts of leaves are difficult for grazers to reach. Specimens from Peru appear to be found in humid habitats, with the specimens studied by
Tovar (1993)
collected from the Abra Malaga of the Cusco region which is relatively humid and receives updrafts of moisture-laden air from the Amazon (
Sylvester et al. 2014
,
2017
). While
P. trichodes
is relatively common in
paramos
of Colombia and Venezuela, it may be that this species is much rarer further south and, in Peru, belongs to a thin band of humid
paramo-like
vegetation that extends from the Peruvian Jalca down through southern Peru and into the Bolivian Yungas (Antoine Cleef, pers. communication).
Other specimens examined.
Colombia.
Boyaca
: Munic. Chiscas, Vereda Rechiniga,
Paramo
de la Mesa,
area
humeda
semiperturbada de
Paramo
, con
Espeletia
,
Puya
,
Ageratina
e
Hypericum
,
6.59515N
,
72.44359W
, 3741 m alt., 3 Mar. 2018, S.P. Sylvester 3091 (K, US, FMB); Munic. Chiscas,
Paramo
de Chacaritas,
limites
entre
paramo
y
superparamo
,
6.62865N
,
72.39440W
, 4064 m alt., 4 Mar. 2018, S.P. Sylvester 3103 (K., US); Munic. Chiscas,
Paramo
el
Penon
, borde de bosque de
Polylepis
,
6.60119N
,
72.43715W
, 3917 m alt., 5 Mar. 2018, S.P. Sylvester 3157 (K, US, FMB, COL, UPTC, SI); Munic. Duitama,
Paramo
de la Rusia, en la carretera que conduce a la
Pena
Negra,
paramo
con rocas expuestas, 5,58389N, 73,053263W, 3970 m alt., 21 Nov. 2017, M. Vorontsova 2218 (K, US, FMB, SI). Munic. Duitama,
Paramo
de la Rusia,
via
que conduce a la Vereda
Avendanos
,
5.93247N
,
73.0798W
, 3726 m alt., 4 Oct. 2017, S.P. Sylvester 3038 (K, US, FMB, UPTC); Munic. Duitama,
Paramo
de Agueros, en la
via
que conduce a la vereda
Avendanos
, Se observa evidencia de fuego y pastoreo,
5.91464N
,
73.07114W
, 3445W m alt., 28 Oct. 2017, S.P. Sylvester 3067ª (K, US, FMB); Munic. Mongua,
Paramo
de Oceta, Valle de Laguna Negra,
vegetacion
de pajonal frailejonal con presencia de pastoreo de vacunos,
5.69525N
,
72.79133W
, 3694 m alt., 29 Nov. 2017, L.E.
Cuta-Alarcon
354 (K, US, FMB).
Santander
: Paramo de la Angostura, Vereda El Mortino,
06°57'30"N
,
72°43'30"W
, 3605 m alt., 17 Nov. 2007, M.C. Gomez 1 (US-3534984).
Santander Norte & Cesar
: Limites entre Santander Norte y Cesar jurisdicciones, Cerro de Oroque, 3700-3900 m alt., 22-27 July 1974, H. Garcia-Barriga 20588 (US29665591; US2966621).
Venezuela.
Merida
: Sierra Nevada, 9000 ft, 1847, Funck & Schlim 1630 (US); Sierra Nevada de Santo Domingo, between partaderos and Timotes, Paramo de Mucuchies, Pico Aguila, 4118 m alt., 21-26 Nov. 1959, H.G. Barclay 9685 (US3044346); Sierra Nevada de Santo Domingo, Paramo de Mucubaji, alrededores de la Laguna Grande, 3560-3600 m alt., 19 Nov. 1959, H.G. Barclay 9546 (US3096576); Sierra Nevada de Santo Domingo, Paramo Laguna de Mucubaji, carretera Barinas-Merida, 4200 m alt., 15 Nov. 1958, B. Trujillo 4072 (US3652663).
Trujillo
: Munic. Bocono, Laguna Eco to Pico Guarigay (summit), Monumento Natural Teta de Niquitao-Guirigay, summit of Pico Guarigay, 3600-3870 m alt., 16 Sep. 2003, B. Stergios 20450 (US00772686); Munic. Bocono, Laguna Larga, via Laguna Las Parias to Laguna Eco, Paramo de Motumbo, Monumento Natural Teta de Niquitao-Guirigay, 3400-3600 m alt., 15 Sep. 2003, B. Stergios 20420 (US00772685); Along the border with Merida state, 3400 m alt., 14 Sep. 2003, B. Stergios 20315 (US00772683); B. Stergios 20358 (US00772684); Monumento Natural Teta de Niquitao-Guirigay, sector Las Veguitas, 3060-3080 m alt., 20-21 Aug. 2002, L.J. Dorr 9157 (US00728039); Monumento Natural Teta de Niquitao-Guirigay, Paramo Guirigay, 3400-3600 m alt., 2-3 Aug. 2002, B. Stergios 19851 (US00728050).
Notes.
Briceno
(2010)
noted the possible relationship of
Agrostis trichodes
to
Podagrostis
based on the rachilla prolongation. While studying specimens of
A. trichodes
from
paramos
of Colombia and Venezuela, SPS noted certain characteristics differed from the type collected in Peru, the protologue, and the description in the treatment of grasses of Peru (
Tovar 1993
). These characteristics, including presence of a rachilla prolongation emerging from the base of the florets, and lemmas sometimes with a short dorsally inserted awn, are also shared by
A. bacillata
and
A. exserta
, and highlight the connection of this species to
Podagrostis
.
The character of awn presence was not noted for this species by
Hitchcock (1927)
nor
Tovar (1993)
, although
Briceno
(2010)
mentions this for Venezuelan material. While
Hitchcock (1927)
highlights the rachilla prolongation as a crucial character for distinguishing this species from other
Agrostis
,
Tovar (1993)
did not mention it. This information is also lacking from the protologues of both
Vilfa trichodes
and
Agrostis bogotensis
. The
Vilfa trichodes
isotype at HAL bears spikelets which lack a rachilla extension, and lemmas that lack awns (Marcus Lehnert and Natalia Tkach, pers. communication). It appears that Oscar Tovar, when preparing his treatment of the grasses of Peru (
Tovar 1993
), had only seen the US isotype fragment, which lacks florets. His mention that the glumes are
'glabrous'
(by which Tovar meant glabrous and smooth) raises ambiguity, although most other characters found in the description and illustration match. The flag leaf ligule of the US isotype fragment reached 1.5 mm long, while
Tovar (1993)
mentions the ligule to measure 2-2.5 mm long, with most material studied from Colombia and Venezuela having flag leaf ligules to 1.7 mm long, with those of the tillers c. 0.5 mm long.
Tovar's
(1993)
description seems to have been based largely on Tovar and
Rivas-Martinez
8076, 8080 from Abra Malaga of the Cusco region of southern Peru, which were not seen by us. The first author visited the Abra Malaga site to conduct extensive field surveys and botanical collecting during different seasons from 2010-2013 (
Sylvester et al. 2014
,
2017
) but no specimens were encountered. Aside from the type, no specimens from Peru have been located despite careful searching through the US herbarium.
Podagrostis trichodes
closely resembles
P. exserta
and
P. bacillata
, considered endemic to alpine grasslands of Guatemala or
paramos
of Costa Rica and Panama, respectively (
Pohl and Davidse 1994
). Key similarities include: a) an overall similar habit (i.e. short tufted herbs with exserted open panicles); b) involute or convolute, acicular or filiform leaf blades; c) presence of a short glabrous rachilla extension emerging from the base of the floret; and d) a short awn often found inserted medially on the lemma dorsal surface. Both
P. bacillata
and
P. exserta
have smooth panicle branches, pedicels, glume surfaces (with only the keels being lightly scaberulous), and lemma surfaces while these are usually lightly to densely scabrous in
P. trichodes
, although specimens have been encountered with almost smooth panicle branches and pedicels [e.g., M.C. Gomez 1 (US3534984), H.G. Barclay 9685 (US3044346), 9546 (US3096576)]. The overall habit of
P. exserta
more closely resembles that of
P. trichodes
than
P. bacillata
, in lacking a visible elongated culm internode and having a shorter panicle (<5 cm long vs. 4-11 cm long in
P. bacillata
). However,
P. exserta
can be differentiated from
P. trichodes
in having smooth leaf blade abaxial surfaces, lemma surfaces, panicle branches, and pedicels (vs. usually scaberulous to densely scabrous, panicle branches and pedicels infrequently smooth in
P. trichodes
), its glume keels and surfaces being mostly smooth with only few prickle hairs found on the keel distally (vs. glume keels often densely scabrous for most their length with surfaces often scabrous distally in
P. trichodes
), and larger spikelets (usually 1.5-2 mm long vs. 1-1.5 mm long in
P. trichodes
).
Podagrostis bacillata
can be differentiated from
P. trichodes
in having culms with at least one visible elongated internode and an exserted node (vs. usually without a visible elongated internode and exserted node in
P. trichodes
), panicles usually larger, 4-11 cm long (vs. 2.5-6 cm long in
P. trichodes
), panicle branches and pedicels generally smooth (vs. usually lightly to densely scabrous, infrequently smooth in
P. trichodes
), longer spikelets, 1.7-2 mm long (vs. 1-1.5 mm long in
P. trichodes
), glumes smooth apart from the lightly scaberulous keel (vs. glume keels often densely scabrous for most their length, with surfaces often scabrous distally in
P. trichodes
), lemmas smooth (vs. lightly to densely scabrous in
P. trichodes
), and rachilla prolongation 3-1.4 mm long (vs. 0.2-0.5 mm long in
P. trichodes
).
Specimens from
paramos
of Departamento
Boyaca
, Colombia, were noted to have the unusual character of glumes being readily caducous at maturity and falling before the floret, with mature inflorescences lacking glumes and only the florets remaining on the pedicels. It is not clear whether this may be a reaction to a pathogen or whether it is taxonomically informative since other specimens sometimes lack this character.
Certain specimens of Freire Apolliniaire are annotated as isotypes of
Agrostis bogotensis
at P (P00740431 [image!]) and NY (NY00327650 [image!], NY00688633 [image!]) that differ in collection dates, collection numbers, and/or localities from the holotype, with NY00688633 also obviously not the same species. These should be disregarded as type material and reexamined. Apolliniaire s.n. K000308373 may be an isotype but the full collection date is missing to help clarify this.