Revision of Muhlenbergia (Poaceae, Chloridoideae, Cynodonteae, Muhlenbergiinae) in Peru: classification, phylogeny, and a new species, M. romaschenkoi
Author
Peterson, Paul M.
Author
Vega, Isidoro Sanchez
Author
Romaschenko, Konstantin
Author
Giraldo-Canas, Diego
Author
Rodriguez, Nancy F. Refulio
text
PhytoKeys
2018
114
123
206
http://dx.doi.org/10.3897/phytokeys.114.28799
journal article
http://dx.doi.org/10.3897/phytokeys.114.28799
1314-2003-114-123
CB70FFE82A46DE6DFFEBFFF8F43A6230
2533527
2.
Muhlenbergia bryophilus (
Doell
) P.M. Peterson, Caldasia 31(2): 279, f. 2
A-B
, 2009.
Fig. 3A, B
Aegopogon
bryophilus
Doell
, Fl. Bras. 2(3):239. 1880. Type: BRAZIL, Minas Gerais, 10 Apr 1879,
A.F.M. Glaziou 11661
(holotype: P-01863266 [image!]; isotypes: C-10016716 [image!], K-000309079 [image!], US-1280026!).
Aegopogon geminiflorus var. muticus
Pilg., Bot. Jahrb. Syst. 27(1-2):25. 1899. Type: Bolivia, La Paz, near Sorata, 1 May 1892,
M. Bang 1307
(holotype: unknown; isotypes: CM-0179 [image!], K-000309080 [image!], NDG-07662 [image!], PUL-00000320 [image!], US-2473254!; W-18930005256 [image!]).
Aegopogon argentinus
Mez, Repert. Spec. Nov. Regni Veg. 17(8-12):145. 1921. Type: ARGENTINA. Salta: Sierra Nevada del Castillo,
P.G. Lorentz & G. Hieronymus 182
(holotype: B?; isotypes: BAA-00001256 [image!], US-75037 fragm. ex B!).
Aegopogon fiebrigii
Mez, Repert. Spec. Nov. Regni Veg. 17(8-12):145. 1921. Type: BOLIVIA. Camacho,
K. Fiebrig 2865
(holotype: B?; isotypes: MVFA-0000127 [image!], US-75308 fragm. ex B!).
Description.
Slender often sprawling, caespitose
annuals
.
Culms
(4-) 6-30 cm long, glabrous below the nodes;
internodes
0.6-6 cm long, glabrous to pilose.
Leaf sheaths
mostly 0.5-4.8 cm long, shorter than the internodes, glabrous to sparingly pilose;
ligules
0.6-1.5 mm long, glabrous, apex mostly truncate, lacerate, auricles absent;
blades
1.5-6 cm long, 0.5
-1.5(-
1.7) mm wide, flat, scaberulent and pubescent above, mostly smooth beneath.
Panicles
2-6 cm long, 0.5-1.2 cm wide, open, loosely-flowered;
primary branches
0.2-0.6 mm long, excluding the awns, one per node, racemosely inserted.
Fertile spikelets
2.4-3 mm long, in fascicles of two, rarely three per branch, often greenish or purplish, the clusters with one short-pedicelled spikelet (bisexual);
pedicels
(0.0-) 0.2-0.5 mm long (fertile spikelets) and the other two spikelets (sterile or staminate) longer pedicelled;
pedicels
about 0.7-1 mm long (sterile or staminate);
glumes
1-1.3 mm long, narrowly acuminate, apex prolonged, aristate;
lemmas
2.4-3 mm long, 3-awned, the central awns (3-) 5-8 (-12) mm long, lateral awns usually 0.8-1.4 mm long;
paleas
2.2-2.8 mm long, puberulent, apex aristate, the awns usually 1-1.2 mm long;
anthers
0.5-0.7 mm long, yellowish.
Caryopses
about 1 mm long, obovoid, light brownish.
Figure 3.
A, B
Muhlenbergia bryophilus
(
Doell
) P. M. Peterson
A
habit
B
spikelet
C, D
Muhlenbergia cenchroides
(Humb. & Bonpl. ex Willd.) P. M. Peterson
C
habit
D
spikelet. Drawings from
Giraldo-Canas
and Peterson (2009)
A, B
drawn from
S.G. Beck 818
(LPB)
C, D
drawn from
S.G. Beck 7464
(LPB).
Distribution.
Muhlenbergia bryophilus
is found in South America, occuring in Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador and Peru.
Ecology.
This species occurs on moist slopes, cliffs, barrancas, canyons, roadsides and along or near springs usually in shaded areas associated with
Cenchrus clandestinus
(
Hochst. ex Chiov.) Morrone,
Bouteloua simplex
Lag.,
Festuca myruos
L.,
Urochloa
,
Veronica
,
Eragrostis
,
Baccharis
,
Salvia
,
Agave
and
Erodium
; 1500-3700 m. Flowering December through May.
Comments.
Muhlenbergia bryophilus
is morphologically similar to
M. cenchroides
and can be separated from the latter in having anthers 0.5-0.7 mm long, the annual habit with culms (4-) 6-30 cm tall and sessile or inconspicuously pedicelled perfect spikelet associated with one (rarely two) staminate or sterile pedicelled spikelet (
Tovar 1993
;
Giraldo-Canas
and Peterson 2009
). The central lemmatal awn length of the sessile or inconspicuously pedicelled spikelet was used by
Beetle (1948)
to differentiate between these two species but we found this measure to be completely overlapping.
Muhlenbergia bryophilus
is sister to a single entry of
M. uniseta
(Peterson 24712) in our new analysis (Fig.
1B
). We have only a single marker (ITS) for
M. bryophilus
, so its alignment may change with additional plastid markers.
Specimens examined.
Peru.
Cusco
: Prov. Anta, Mollepata-Takawana, C. Vargas C. 19050 (USM); Prov. Urubamba, SW facing slope of Machu Picchu Mountain, V. Ugent 5324 (USM);
Junin
: Prov. Huancayo, Abajo de Pariahuanca, O. Tovar 7895, 7904 (USM); Cerro E of Huancayo, O. Tovar 2137 (USM);
La Libertad
: Prov. Bolivar, W of Longotea, 0.5 km towards San Vicente,
7°2'35.6"S
,
77°52'39.8"W
, 3202 m, 31 Mar 2008, P.M. Peterson 21966, R.J. Soreng & J. Montoya Quino (US, USM);
Lima
: Prov. Canta, 8 km SW of San Jose Canta towards Huamantango,
11°31'10"S
,
76°42'16.3"W
, 2770 m, 28 Mar 2004, P.M. Peterson & N. Refulio
Rodriguez
17995 (US, USM);
Piura
: Prov. Huancabamba, La Beatita, S. Llatas Quiroz 1850, 1851 (CPUN);
Puno
: Prov. Sandia, Debajo de Cuyocuyo, R. Ferreyra & A. Vera Beuner 16636 (USM).