Agrostis and Podagrostis (Agrostidinae, Poaceae) from paramos of Boyaca, Colombia: synoptic taxonomy including a key to Colombian species
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
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
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
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
151
107
160
http://dx.doi.org/10.3897/phytokeys.151.50538
journal article
http://dx.doi.org/10.3897/phytokeys.151.50538
1314-2003-151-107
42D1EB2DF0545744B92BFCCCB395C45B
Podagrostis trichodes (Kunth) Sylvester & Soreng, PhytoKeys 148: 42. 2020
Fig. 11
Vilfa trichodes
Kunth, Nov. Gen. Sp. [H.B.K.] 1: 139. 1816.
Agrostis trichodes
(Kunth) Roem. & Schult., Syst. Veg. (ed. 15 bis) 2: 361. 1817.
Aira trichodes
(Kunth) Spreng., Syst. Veg., ed. 16 [Sprengel] 1: 276. 1824.
=
Agrostis bogotensis
Hack., Repert. Spec. Nov. Regni Veg. 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.)).
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; isotypes: HAL (HAL0106929 [image!]), US (US75364! fragm. ex P)).
Description.
Perennial herbs
, forming short dense tufts, with the basal mats reaching c. 4-11 cm tall and inflorescences well-exerted from the basal foliage.
Tillers
intravaginal, without cataphylls.
Culms
7-20(-30) cm tall, erect, simple, delicate, with 0(-1) nodes exerted at flowering, smooth.
Leaves
mostly basal, glabrous, finely to densely scabrous;
ligules
0.7-1.7(-2.5) mm long, of basal leaves and tillers 0.7-1.2 mm long, of upper culm leaves generally longer, truncate to obtuse, slightly to usually strongly decurrent with the sheath, abaxial surface smooth or rarely scaberulous;
blades
1-4 cm long, 0.3-0.4 mm wide in diameter, involute or convolute, acicular to capillaceous and filiform, usually curved, rigid, apices acute.
Panicles
2-5(-6) cm long, 1-2(-3) cm wide, lax and open, ovoid, slightly to usually greatly exerted from the basal foliage, lateral branches with spikelets in the distal 1/3, the lower 2/3 naked, long, ascending to patent, not held close to the central inflorescence axis, central axis and panicle branches usually scaberulous or sometimes smooth;
pedicels
1-2 mm long, usually longer than the length of the spikelets, not or slightly dilated at their apex, smooth to usually lightly scabrous.
Spikelets
1-1.5 mm long;
glumes
equal or subequal, the lower often slightly longer than the upper, 1-veined, keels scabrous just in the distal 1/3 to throughout their length, surfaces smooth a scabrous distally, apices obtuse to acute;
floret
almost equaling the length of the glumes or slightly shorter;
calluses
glabrous;
lemmas
1-1.5 mm long, glabrous, moderately to densely scabrous (
'smooth'
possibly mentioned by
Tovar 1993
!), sometimes granulose, apex obtuse, faintly to strongly 5-veined, awn lacking or to 0.5 mm long, straight, inserted medially or in the upper half of the lemma, not surpassing the glumes;
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;
rachilla
usually 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;
anthers
0.4-1 mm long.
Figure 11.
Podagrostis trichodes
A
spikelet, lateral view with floret detached and raised above the glumes, rachilla prolongation indicated by an arrow
B
floret, lateral view, rachilla prolongation indicated by an arrow
C
whole plant. Images:
A
,
B
Rodriguez
(UPTC 22204),
C
Cuta-Alarcon 362 (FMB).
Distribution and ecology.
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. May also occur in Bolivia according to
Tovar (1993)
, although no specimens have been verified. No specimens have been verified from Ecuador, although it is mentioned to occur there (
Hitchcock 1927
;
Tovar 1993
;
Jorgensen
and Ulloa-Ulloa 1994
;
Jorgensen
and
Leon-Yanez
1999
;
Luteyn 1999
). A common element in moderately grazed areas and path-sides of
Boyacan
paramo
.
Other specimens examined.
See
Sylvester et al. (2020)
.
Notes.
The combination of open panicle, spikelets <1.5 mm long, florets which subequal the apex of the glumes, a palea reaching from (2/3)
3/4
to subequaling the lemma, lemmas awnless or with a short (<0.5 mm long) straight awn inserted in the upper
1/2
of the lemma, and a short glabrous rachilla prolongation emerging from under the palea are diagnostic for this species. The rachilla prolongation (Fig.
11
, indicated by arrows) is sometimes difficult to see if it is tucked between the flanges of the palea, and so spikelet dissection is necessary. All species of
Podagrostis
from Colombia have involute or convolute leaf blades that can easily separate them from species of
Agrostis
with well-developed paleas.
Similar species.
Aside from
Podagrostis bacillata
(Hack.) Sylvester & Soreng and
P. exserta
(Swallen) Sylvester & Soreng that are found in Central America (see
Sylvester et al. 2020
),
P. trichodes
could possibly be mistaken for shorter plants of
A. perennans
which can have short spikelets as small as 1.8 mm long.
Agrostis perennans
s.l. has florets which usually do not reach past
3/4
the length of the glumes, a minute palea less than
1/4
the length of the lemma, and lacks a rachilla prolongation.