CONTRIBUTIONS TO THE GENUS FESTUCA (POACEAE: POEAE) IN MEXICO AND A KEY TO THE CENTRAL AMERICAN SPECIES

2007·9.5 MB·English

by  Stephen J Darbyshire

AND
CONTRIBUTIONS TO THE GENUS FESTUCA (POACEAE: POEAE) MEXICO
IN
A KEY TO THE CENTRAL AMERICAN
SPECIES
Stephen
Darbyshire
J.
andArgi-Food Canada
Agriculture
and
Eastern Cereal Oilseed Research Centre
Wm.
Central Experimental Farm, Saunders BIdg. #49
Ottawa, Ontario, KIA 0C6, CANADA.
ABSTRACT
A
new species, Festuca longiligula (Poaceae: Poeae), is described from the state of Coahuila, Mexico. Names and descriptions are
provided for two nothospecies from central Mexico, Festuca xgonzalez-ledesmae and F. xmiscella, putative hybrids of F. livida x F.
hephaestophila d^nd F. livida x F. tolucensis, respectively. Observations on some unusual morphological characteristics of Festuca (subgenus
A known
Hellerid) livida are presented. key to the species of Festuca in Central America is provided.
new
Key Words: Festuca, species, Mexico, Central America, hybridization, nothospecies, subgenus Helleria, keys
RESUMEN
Se describe una nueva especie, Festuca longiligula (Poaceae: Poeae), del estado de Coahuila, Mexico. Se dan nombres y descripciones de
dos nothospecies de Mexico central, Festuca xgonzalez-ledesmae y F. xmiscella, hibridos putativos de F. livida x F. hephaestophila y F.
livida X F. tolucensis respectivamente. Se presentan observaciones de algunas caracteristicas morfologicas inusuales de Festuca (subgenero
,
Helleria) livida. Se aporta una clave de las especies conocidas de Festuca en America Central.
The pioneering work of E.B. Alexeev on the taxonomy of Festuca in Mexico and Central America (Alexeev
ground work on Not
1980, 1984) set the for further detailed investigations the genus. all of his described taxa
A
have been widely accepted Soreng 2003) and some await further study. working of species
(cf. et al. list
new some
given in Table This paper describes species (including nothospecies), contributes additional
is 1.
known
observations and presents an updated key the species from Mexico and Central America.
to
Festuca longiligula Darbyshire, nov (Figs. 2A, 2B, 3A) Mexico. so
S.J. sp. 1, Type: Coahuila: de Saltlllo, cejay ladera
S de sierra La Vlga, subalplna, 3700 msnm, 22 Aug 1986, [A.] McDonald 2102 (iiolotype: TEX: isotype: WIS, XAL (non vidi).
Plantae perennes caespltosae, innovatlonibus Intravaginallbus praedltae. Culmi 70-90 cm leves. Vaginae foliorum Inia basi tan-
alti,
mm
tum emortuorum non
integrae, leves vel scabrae; vaginae foliorum in fibras longitudinales solutae; ligulae scariosae, (2-)5-9.5
mm
cum
longae, laceratae; laminae foliorum innovationum conduplicatae, 0.8-1.5 diametri, abaxialiter scabrae, adaxialiter hirsutae,
cum
9-11 nervis, 7-11-costatae, sclerenchymate abaxialiter annulo continuo subepidermali disposito, sclerenchyma fasciculis venas
cm
majore abaxialiter et interdum adaxialiter conjunctis, cellulis buUiformibus destitutae vel cellulae minutae. Paniculae 10-22 longae,
mm
cum
pyramidales, laxae, axe distali et ramulis scabris. Spiculae (6-)7.5-13 longae, ovatae ad ellipsiodeae, 4-7 flosculis; glumae
ovatae ad lanceolatae, scariosae vel margine late scariosae, glabrae vel pleurumque scabrosae ad hispidulae dimidio superanti; glumae
mm mm
cum cum
inferiores 3.4-5. 5(-5. longae, nervis; glumae superiores 4.5-6.5 longae, (l-)3(-5) nervis; rachillae usque
7) 1(3)
mm mm
ad 1.5 longae, hispidulae unilateraliter; lemmatae (5-)6-7 longae, lanceolatae ad anguste ovatae, glabrae vel apice scabra ad
cum
hispidula, 5(-7) nervis obscuris, apice late scariosa, obtusa ad abrupte acuta, interdum emarginata ad plus minusve bidentata,
mm mm
inermia vel praedita interdum arista brevissima usque ad 0.5 longa; paleae 5-7 longae, apice bidentatae, inter venas et saepe in
mm
marginalibus distalibus hispidulae, venae scabroso-ciliatae prope apicem ad 1/2; antherae 2.5-3.3 longae; ovarium apex sparsim
mm.
hispidulus. Caryopses 3.5-4.5 x 0.8-1.5
Plants perennial, caespitose, shoots intravaginal. Culms erect or slightly decumbent the base, 70-90 cm
at
smooth and glabrous. Leaf sheaths with the margins closed only the base, smooth and glabrous or
tall, at
mm
sometimes scabrous, not decaying into longitudinal auricles absent; ligules scarious, (2-)5-9.5
fibres;
mm
long, lacerate; leaf blades of vegetative shoots conduplicate, 0.8-1.5 in diameter, abaxially scabrous,
adaxially hirsute, with 9-11 veins and 7-11 adaxial ribs; sclerenchyma in a continuous abaxial band, fas-
cicles joining the major veins with abaxial epidermis and with adaxial fascicles opposite veins sometimes
joining veins to form girders (Fig. bulliform cells absent or inconspicuous. Inflorescence paniculate.
2);
-
J. Bot. Res. Inst. Texas 1 (2): 827 840. 2007
.... .
828 Journal of the Botanical Research Institute of Texas
1(2)
Table 1. Species of the genus Festuco in Mexico and Central America and known distributions (primarily from literature sources)
Species Mexico (States) Central America
(other countries)
aequipaleata
F. E. Fourn., Biol. Centr.-Amer. Veracruz
3(20):581.1885.
aguana (Moscow & Panama
Alexeev, Zhurn. ? Guatemala,
f. E.B. Bot.
Leningrad) 66:1 493, 1.1981.
f.
F. amplissima Rupr., Bull. Acad. Roy. Sci. Bruxelles Chiapas, Distrito Federal, Durango, Costa Rica, Guatemala,
Panama
9:236.1842. Guerrero, Hidalgo, Mexico,
Jalisco,
Nuevo
Michoacan, Morelos, Leon,
Puebla,Tlaxcala, Veracruz
F. arundinacea Schreb., Spicil. Lips.:57. 771 Mexico, Veracruz Costa Rica, Guatemala
Fl.
1
asperella Alexeev, Bot Zhurn. (Moscow & Mexico
F. E.B.
496-1
Leningrad) 66:1 497, 981
f. 1 1
.
& Novon
F. bajacaliforniana Gonz.-Led. S.D. Koch, Baja California
4:28-30, 1994.
3.
f.
beamanii Alexeev, Zhurn. (Moscow & Guatemala
F. E.B. Bot.
500-1
Leningrad) 66:1 501 981
2.
f. 1
,
bidenticulata Alexeev, Bot Zhurn. (Moscow & Veracruz
F. E.B.
Leningrad) 66:1 496, 1.1981.
f.
F. breviglumis Swallen, Contr. U.S. Natl. Herb. Jalisco, Michoacan, Morelos, Oaxaca Costa Rica, Guatemala,
Panama
29:398.1950.
F. callosa (Piper) St. Yves, Candollea 2:291 925. Oaxaca, Puebia
1
.
cartagana (Moscow & Panama
Alexeev, Zhurn. Costa
F. E.B. Bot. Rica,
291-1
Leningrad) 67:1 292, 982.
f. 1 1
.
Panama
F, chiriquensis Swallen, Ann. Missouri Bot. Gard. Costa Rica,
30:116.1943.
coahuilana & Novon
Gonz.-Led. Koch, Coahuila
F. S.D. 4:
27-27, 1994.
2.
f.
Novon Chihuahua
diclina Darbysh., 995.
F, 5:1 29, 2.
f. 1 , 1
& Mem.
F. filiformis Pourret, Hist. Acad. Roy. Sci. Costa Rica
Toulouse 3:319. 1788.
xgonzalez-ledesmae
Darbysh. Mexico, Veracruz
F, TIaxcala,
guatemalica Alexeev, Zhurn. (Moscow & Mexico Guatemala
F. E.B. Bot.
498-1
Leningrad) 981
66:1 500,
2.
f. 1
[= willdenowiana
F. ?]
F. hephaestophila Steud., Syn. Glumac. Mexico, Nuevo Leon, Puebia, Tamaulipas, Costa Rica, Guatemala
PI.
1:310.1854. TIaxcala, Veracruz
herrerae Davidse, Novon 2:322-324, 992. Costa Panama
F. Rica,
f. 1 1
.
F. hintoniana E.B. Alexeev, Bot. Zhurn. (Moscow & Coahuila, Nuevo Leon
Leningrad) 67:1 292, 1.1982.
f.
(Moscow &
F.jaliscana Alexeev, Bot. Zhurn. Jalisco
E.B.
493-1
Leningrad) 66:1 495, 981
f. 1 1
.
F. ligulata Swallen, Amer. Bot. 9:436, 932. Coahuila
J. 1 f. 1 1
.
F./iVida(Kunth)Spreng.,Syst.Veg. 1:353. 1825. Mexico, Puebia, TIaxcala, Veracruz
longiligula Darbysh. Coahuila
F.
F. lugens Fourn.) Hern.-XoL, Bol. Soc. Bot. Mexico Chiapas, Chihuahua, Distrito Federal, Honduras
(E.
23:165.1958. Hidalgo, Mexico, Michoacan,
Jalisco,
Morelos, Oaxaca, Puebia, San Luis Potosi,
Tamaulipas, Veracruz
xmiscella Darbysh. Mexico
F.
F. orizabensis E.B. Alexeev, Bot. Zhur. 66: Distrito Federal, Durango, Jalisco, Mexico,
497-1
498, 1981. Puebia, Veracruz
2.
1 f.
ovina
F. Sp. :73-74. 753. Costa Rica
L., PI. 1 1
panamica (Moscow & Panama
Alexeev, Zhurn.
F. E.B. Bot.
290-1
Leningrad) 67:1 291 982.
, f. 1 . 1
.
Darbyshire, Festuca Mexico and a key to the Central American species 829
in
ABLE 1. continued.
Species Mexico (States) Central America
(other countries)
F.pring/e/ Yves, Candollea 2:305-307, 53. 1925. Chihuahua, Durango, Jalisco,
St.
f.
San
Luis Potosi
roblensis Gonz.-Led., Novon 47-1 998 Guanajuato, Zacatecas
F. 8:1 49,
f. 1 1
.
F. rose! Piper, Contr. U.S. Natl. Herb. 0:45. 906. Distrito Federal, Guerrero, Jalisco, Mexico, Guatemala
1 1
Michoacan,Morelos,Tlaxcala, Veracruz
F.rubraUSp. 1:74. 1753. Chihuahua, Mexico, Nuevo Leon Costa Rica
PI.
rzedowskiana Alexeev, Zhurn. (Moscow & Mexico
F, E.B. Bot.
Leningrad) 66:1 500, 1981.
2.
f.
F. subverticUlata (Pers.) E.B. Alexeev, Novosti Sist. based on a probable label error
Vyssh. 1980.
Rast. 7:52, 2.
1 f.
(Moscow & Panama
swallenii Alexeev, Zhurn.
F, E.B. Bot.
Leningrad) 495-1496, 981
66:1
f. 1 1
.
talamancensis Novon
F. Davidse, 2:324, 992. Costa Rica
f. 1 1
.
tancitaroensis Gonz.-Led. & Koch, Novon Michoacan
F. S.D.
4:25-27, 1.1994.
f.
F. tolucensis Kunth, Nov. Gen. Sp. 53. 81 5. Chiapas, Distrito Federal, Jalisco, Mexico, Costa Rica, Guatemala
1 :1 1
Michoacan, Morelos, Oaxaca, Puebia,
San Veracruz
Luis Potosi, TIaxcala,
& Novon Nuevo
va/£/e5/iGonz.-Led. Koch, Coahuila, Le6n,Tamaulipas
F. S.D. 8:
149-151, 2.1998.
f.
F. willdenowiana Schult & Schult. Add. ad Mant. Distrito Federal, Mexico, Michoacan, Guatemala
f..
3:650.1827. Puebia, TIaxcala, Veracruz
cm
10-22 long, pyramidal, lax, rachis glabrous below and scabrous above; branches lax, l(-2) per lower
mm
node, scabrous. Spikelets (6-)7.5-13 long, ovate to ellipsoid, more or less distal on the branches, with
4-7 glumes
florets; ovate to lanceolate, scarious or with broad scarious margins, glabrous or frequently
mm
scabrous to hispidulous in the upper half; lower glumes 3.4-5. 5(-5. 7) long, with l(-3) veins; upper
mm mm
glumes 4.5-6.5 long, with (l-)3(-5) veins; rachilla up to 1.5 long, unilaterally hispidulous op-
mm
lemmas
posite to the floret; (5-)6-7 long, lanceolate to narrowly ovate, glabrous or apically scabrous
or hispidulous, with 5(-7) obscure veins, the apex broadly scarious, obtuse to abruptly acute, sometimes
mm
emarginate to more or less bidentate, awnless or with a short mucro arising between the lobes to 0.5
mm
5-7
long; paleas long, bidentate, apically hispidulous between the veins and sometimes on the up-
mm
per margins, veins scabrous-ciliate in the upper 1/2-2/3; anthers 2.5-3.3 long; ovary apex sparsely
mm mm
Caryopses
hispidulous; styles 3.5-4.5 long, 0.8-1.5 wide.
2.
km
MEXICO.
Additional collection examined: Coahuila: Mpio. de Arteaga, Sierra la Viga 6 al E de Jame, Puerto Maravillas, 25°22'N
100°34'W, bosque de Pinus rudis, ayacahuite, Pseudotsuga, Abies, Quercus, con arbustos de Ceanothus y Pinus culminicola 3000-3150
P.
,
&
m, 16 Sep 1989 J.A. Villarreal et al. VR-1983 (TEX). Eig. 2B.
Festuca longiligulata belongs to subgenus Festuca section Breviaristatae and is similar to F. thurberi Vasey of
the southern Rocky Mountains in the dense caespitose habit, glumes thinner in texture than the lemmas
and long ligules. differs from the latter in the more ovate lemmas which are obtuse (sometimes abruptly
It
acute) to somewhat truncate or emarginate with a wide scarious margin, while in thurheri the lemmas are
F.
more narrowly ovate to lanceolate and tapering to an entire acute apex with narrow scarious margins (Fig.
mm, mm,
The anthers of longiligulata are usually shorter, 2.5-3.3 versus 3-4.5 and the ovary apex
3). F. is
sparsely hispidulous, versus densely hispidulous. These characters and the isolated distribution in the Sierra
Madre Oriental suggest that F. longiligula is a distinct species. It differs from F. ligulata in the more densely
mm, mm,
caespitose habit, usually longer ligules ((2-)5-9.5 versus 2.5-3.5 mm), lemmas (5-7 versus 4.5-6
mm) mm,
and mm).
anthers (2.5-3.3 versus 1.5-2.6
830 Journal of the Botanical Research Institute of Texas
1(2)
UNIVERSITY OF
HERBARIUM
cm
Wl
= =
Fig. 1 Festuca longiligula holotype specimen, McDonald 2102 (TEX). Scale bar: left 2 inches; right 5 cm
.
Darbyshire, Festuca Mexico and a key to the Central American species 831
in
A
- B -
Fig. 2. Innovation shoot leaf blade cross sections of Festuca longiligula. \\o\otypQ, McDonald 2102; Paratype, Villarreal et ai VR-1983.
- -
Fig. 3. Lower lemmas. A Festuca longiligula, McDonald 2102 (holotype); B Festuca thurberi, Swollen 6608 (DAO).
Festuca subgenus Helleria
In his surveys of Festuca Alexeev (1980) established F. subgenus Helleria (E. Fourn.) E.B. Alexeev (Novost. Sist.
= &
Vyssh. Rast. 17:51. 1980; Helleria E. Eourn., Mex. 2:128. 1886, non Nees Martius, 1824; Hellerochloa
Pi.
Rauschert, Taxon 31:561. 1982) in which he included F. livida as the sole species. The long glumes (longer
than the lemmas and usually enclosing the whole spikelet) and the unusual strongly drooping panicles were
cited as uniquely distinctive characteristics within the genus Festuca. Alexeev interpreted these characteristics
as a highly specialized cryomorphic adaptation to the alpine habitats in which the species occurs. Other
characteristics of livida are similarly advantageous in these rigorous climatic conditions. The small anthers
F.
mm
(0.8-1.5 long) and usually non-exserted stamens and stigmas are typical of a cleistogamous habit. The
anthers dehisce an early stage of inflorescence development with pollen being released into the cavity
at
832 Journal of the Botanical Research Institute of Texas
1(2)
between the lemma and palea. The anthers dehisce at the level of the stigmas and remain entangled in the
stigmatic branches as the caryopsis matures. The leaf sheaths of shoots and culms are loose (inflated), trap-
ping air and providing insulation for the developing tissues within. Other Central American alpine species
of Festuca have loose flag leaf sheaths, but this characteristic is pronounced in F. livida.
The pendulous form of the panicle in F. livida is unusual in that the rachis is lax right to the lowest
inflorescence node. The lowest rachis internode scarcely wider than the single branch the lower node,
is at
many
giving the inflorescence the appearance of consisting of two branches the lower node. As in spe-
at
cies of Festuca there is a ring of tissue associated with the lowest inflorescence node. In F. livida it is usually
mm
well developed bearing a pointed tip and sometimes extending into short bract up to 25 long. In other
may
Central America species of Festuca^ the ring of tissue bear a pointed but scarcely more than
tip, it is 1
mm
long. Another unusual characteristic of F. livida is the distinctly swollen and slightly flattened upper
culm internode with a large inner cavity (Fig.
4).
Two chromosome counts have been reported n = 14 (Nevado de Toluca; Beaman 1962)
for F. livida, et al.
and n = 21 (Cofre de Perote; Gonzalez-Ledesma 1991). Meiosis of plants from Cofre de Perote was, however,
disrupted (Gonzalez-Ledesma 1991), indicating pollen fertility problems. Pollen from anthers of 9 herbarium
specimens (DAO) showed a considerable range of development and stainability in lactophenol cotton blue
preparations. Even though most anthers seemed be normally dehisced, conservative estimates of pollen
to
When
0-20%.
viability ranged from slightly less stained and/or non-spherical (but not collapsed) grains were
2-48%
deemed
to be possibly fertile, calculations suggested that of pollen grains might be viable. However,
may
low pollen viability does not necessarily present a fertility handicap for cleistogamous grasses and in
fact be an adaptive conservation of resources. Field observations in 1997 at Cofre de Perote (19°29'42"N,
97°08'55"W) and La Malinche indicated that large numbers of plants bore inflorescences with abortive
caryopses, although most florets usually contained dehisced anthers. It is possible that unusual climatic
conditions in that season caused caryopsis abortion, although given the low proportion of stainable pollen,
may
lack of caryopsis development have been the result of failed pollination.
many
The specialized morphological and anatomical features of unique or highly unusual in
F. livida,
Festuca, provide support for the recognition of the separate genus Hellerochloa. However the taxon is clearly
related to the members of Festuca subgenus Festuca, as indicated by the similarity of the vegetative shoot
structure, leaf blade anatomy (both in cross section and the abaxial epidermis) and ovary/caryopsis mor-
phology, as well as the spontaneous hybridization with at least F. hephaestophila and F. tolucensis (see below).
In spite of the fact that intergeneric hybrids have been reported between most genera in Loliinae (except
many
Leucopoa) and genera in Poeae, and that exhibits several unique or unusual characters, the
F. livida
recognition Hellerochloa seems premature.
o\^
Two
spontaneous hybrids, F. livida x F. hephaestophila and F. livida x F. tolucensis are sterile, intermedi-
in many morphological characters and not uncommon in areas where the parental species come into
ate
How
F
contact. the largely cleistogamous livida is able to hybridize with sympatric species of Festuca is yet
be determined.
to
Festuca xgonzalez-ledesmae Darbyshire, nothosp. nov. (Festuca (Kunth) Willd. ex Spreng. x Festuca
livida
S.J.
Nees N
ex Mexico.
hephaestophila Steudel). (Fig. 5). Type: Veracruz: Mpio. de Perote, Cotre de Perote, lado en la base
del macizo rocoso que esta en la cima, pastizal de Festuca, Calamagrostis Trisetum, Agrostis y Deschampsia, alt. 4050 m, 15 Sep 1986,
,
&
DAO
M. Gonzdlez-LeAesma Vera C. 196 (holotype: 683891; isotype: CHAPA).
P.
Inter Festuca livida et Festuca hephaestophila intermedia est. Plantae perennes caespitosae, interdum rhizomatibus brevibus praeditae,
cm
innovationibus intravaginallbus praeditae. Culmi 4.5-22 alti, erecti, glabri, internodia superne interdum leviter tumida. Vaginae
foliorum ima basi tantum integrae, leves, plus minusve inflatae; vaginae foliorum emortuorum in fibras longitudinales plus minusve
mm mm
solutae; ligulae 0.2-l(-1.5) longae; laminae foliorum conduplicatae, (0.3-)0.4-0.9 diametri, apice acuto ad obtuso, abaxialiter
cum cum
glabrae, adaxialiter hirsutae, 5-7 nervis, 5-7-costatae, sclerenchyma fasciculis marginalibus, venas majore abaxialiter, rare
cm
adaxialiter conjunctis, cellulis buUiformibus destitutae. Paniculae (2-)3-6 longae, plus minusve erectae, axe distali et ramulis
mm
cum
scabris. Spiculae 7-ll(-13) longae, ellipsiodeae, (2-)3-4(-5) flosculis; glumae glabrae ad scabrae vel hispidulae, subulatae
mm mm
ad lanceolatae vel tantem ellipsoideae, inermes vel arista usque ad 0.3 longa praeditae; glumae inferiores (5.8-)6.5-8.5(-9)
mm
cum cum
longae, lanceolatae vel ovatae, 1-3 nervis; glumae superiores (6.5)7-9.5(-10) longae, 3-5 nervis; rachillae usque ad 1.5
Darbyshire, Festuca Mexico and a key to the Central American species 833
in
mm
2
Fig. 4. Festuca livida, hand cross section of upper culm internode about 1 cm from apex.
mm mm
cum
longae, hlspldulae unllateraliter; lemmatae 6.5-8. 5(-9. longae, lanceolatae ad ellipsoideae, scabrae ad hirsutae, 5 nervis,
5)
mm mm
apice interdum bldentata, inermla vel plerumque praedita arista (0.3-)0.8-2.5(-3.4) longa; paleae 5.5-7.5 longae, Inter venas
mm
cum
saepe In marginallbus dlstalibus hlspldulae, venae prope aplcem ad 2/3(-3/4) trlchomatlbus; antherae (l-)1.2-2 longae,
et
plerumque Indehlscentes; ovarium apex glabrus vel sparslm hlspldulus. Caryopses non praedltae.
Intermediate between livida and hcphaestophila. Plants perennial, densely caespitose, short rhizomes
F. F.
Culms cm
sometimes present, shoots intravaginal. 4.5-22 erect, glabrous throughout, upper internode
tall,
sometimes slightly swollen. Leaf sheaths closed only the base, glabrous, more or less loose and disin-
at
mm mm
tegrating into fibres with age; ligules 0.2-l(-1.5) long; leaf blades conduplicate, (0.3-)0.4-0.9
in diameter, apex abruptly acute to obtuse, abaxially glabrous (rarely sparsely scabrous), adaxially hirsute,
with 5-7 and 5-7 sclerenchyma margins and
veins adaxial ribs, in fascicles at the abaxially at the veins,
cm
rarely small adaxial fascicles, bulliform cells absent. Inflorescence paniculate, (2-)3-6 long, erect,
stiffly open, axis distally scabrous, branches scabrous, a single branch at lower node. Spikelets 7-ll(-13)
mm
glumes
long, ellipsoid, with (2-)3-4(-5) florets; glabrous to scabrous or hispidulous (especially above),
mm
subulate to lanceolate or sometimes narrowly ellipsoid, unawned or with an awn up to 0.3 long; lower
mm
glumes upper glumes
(5.8-)6.5-8.5(-9) long, lanceolate or ovate, with 1-3 veins; (6.5-)7-9.5(-10)
mm mm
long, with 3-5 veins; rachilla up to 1.5 long, unilaterally hispidulous opposite to the floret; lem-
mm
mas
6.5-8.5(-9.5) long, lanceolate to ellipsoid, scabrous to hirsute, with 5 veins, bidentate or entire,
mm mm
unawned awn
or usually with an (0.3-)0.8-2.5(-3.4) long; paleas 5.5-7.5 long, hispidulous between
the veins and sometimes on the upper margins, veins with trichomes from the apex about 2/3(-3/4)
to to
mm
the base; anthers (l-)1.2-2 long, mostly indehiscent; ovary apex glabrous or sparsely hispidulous.
Caryopses
not formed.
MEXICO.
Additional collections examined. Mexico: Nevado de Toluca, talus slopes and rocky S. rim Inside crater, 3 Jul 1Q64, G. Mick
& NO
K. Roe 198. Tlaxcala: vertlente del volcan La Mallnche, zacatonal de Festuca y Calamagrostis suelo arenoso, 4080 m, 16 Sep
alt.
^
&
NE
1986, M. Gonzdlez-Ledesma P. Vera C. 205\ La Mallnche volcano, SE of Tlaxcala, of Puebla, 19°14'02"N 98''0r56"W, alpine talus
and sollfluctlon slopes, plants Inclose proximity to F. livida and F. hcphaestophila, mostly on windward side of ridges and peak, 4290 m,
&
22 Sep 1997, Darhyshire M. Gonzdlez-Ledesma 4824. Veracruz: summit of Cofre de Perote, 19°29'42"N 97°08'55"W, alpine talus
S.J.
&
and sollfluctlon 4140 m, 20 Sep 1997, Darhyshire M. Gonzdlez-Ledesma 4794A.
sites,
S.J.
has appearance The branches
Tlie inflorescence of xgonzalez-ledesmae the erect of hcphaestophila.
tfie F. F.
may
be stiffly spreading, but the lower branch and lower rachis internode are not drooping to pendulous as
in F. livida. The glumes are broadly to narrowly lanceolate and almost as long as or longer than the adjacent
834 Journal of the Botanical Research Institute of Texas
1(2)
cm
\n
HERBfiRIO-HDRTORJO DEL CDIEBIO DE PDSTSRfiDUADDS (EHfiPfl)
nUKQ
CHAPIN60,
hcpkckosTofm!^.
MEHCG. VERACRU2: Mpio. dp Perote. Cofre de Perote, lado N
en la basE del sacizD rocDso que esta en la ciia. Pastnal
de Festuca. CaUaaqrostis Trisetui, flgrgstis
. y
EeschaBpsia
.
flit. 4 050 «. 15-I1(-19B6
Planta glauca, frecuente.
H. Gonzaiez-Ledesna 196 P. Vera I.
y
= =
&
Fig. 5. festuca xgonzalez-ledesmoe holotype, Gonzdiez-Ledesma Vera 196 (DAO). Scale bar: left 2 inches; right 5 cm.
Darbyshire, Festuca Mexico and a key to the Central American species 835
in
lemmas, whereas they are broadly lanceolate to ellipsoid and distinctly shorter than the adjacent lemmas in
F. hephaestophila. The lemmas of the hybrid are scabrous to hispid at least in the upper third and sometimes
throughout, whereas they are glabrous or only slightly scabrous to hispidulous at the very apex in F. hepha-
A
estophila. comparison of additional characters is given in Table 2. In lactophenol cotton blue preparations
0-2%
from the type collection, of pollen grains were evenly stained and/or regularly formed. This hybrid was
who
recognized by Manuel Gonzalez-Ledesma described in some detail (Gonzalez-Ledesma 1991).
first
it
Festuca xmiscella Darbyshire, nothosp. nov. (Festuca (Kunth) Willd. ex Spreng. x Festuca
livida tolucensis
S.J.
Kunth). Mexico.
(Fig. 6). Typr: Mexico: E slope of Nevado de Toluca, near gate to crater, IQ^'IS'N 99''45'W, alpine solifluction
&M. DAO
sites, about 4000 m, 26 Sep 1997, Darbyshire Gonzdlez-Ledesma 4851 (holotype: 811264).
S.].
Inter Festuca livida et Festuca tolucensis intermedia est. Plantae perennes caespitosae, innovationibus intravaginalibus praeditae. Culmi
20-60 cm
alti, erecti, scabri ad hispiduli, internodia superne interdum leviter tumida. Vaginae foliorum ima basi tantum integrae, leves
mm
vel scabrae, plus minusve inflatae; vaginae foliorum emortuorum in fibras longitudinales non solutae; ligulae (0.5-)l-2.5 longae;
mm
laminae foliorum conduplicatae, (0.5-)0.7-1.5(-2.1) diametri, apice attenuato, abaxialiter glabrae vel scabrae, adaxialiter hirsutae,
cum
7-9 nervis, 7-9-costatae, sclerenchymate abaxialiter annulo continuo subepidermali disposito, fasciculis adaxialiter interdum
cum cm
venas, cellulis buUiformibus destitutae. Paniculae 5-15(-20) longae, laxae et nutantes, axe distali et ramulis scabris. Spiculae
mm
cum
9-14(-16) longae, obovatae vel late ellipsiodae, 4-6(-7) flosculis; glumae glabrae, scabrae ad hispidulae, subulatae ad lanceolatae,
mm mm
cum
inermae vel arista usque ad longa praeditae; glumae inferiores (6.3-)7-10(-11.5) longae, 1-3 nervis; glumae superiores
1
mm mm
cum
(7.5-)8-ll(-13.8) longae, 3-5 nervis; rachillae usque ad 1.5 longae, hispidulae unilateraliter; lemmatae (7.5-)8-10(-12)
mm
cum
longae, lanceolatae, scabrae, papillosae vel hirsutae, 5 nervis, apice plerumque bidentata, inermia vel plerumque praedita arista
mm mm
cum
(0-)l-2(-2.9) longa; paleae 6-7.5 longae, inter venas et in marginalibus distalibus hispidulae, venae prope apicem ad 3/4
mm
trichomatibus; antherae 1.5-4.5 longae, plerumque indehiscentes; ovarium apex glabrus. Caryposes non praeditae.
Intermediate between livida and tolucensis. Plants perennial, densely caespitose, shoots intravaginal.
F. F.
Culms 20-60 cm scabrous hispidulous, upper internode sometimes Leaf
tall, erect, to slightly svv^oUen.
sheaths closed only at the base, glabrous or scabrous, somewhat loose, not splitting into fibres with age;
mm mm
ligules (0.5-)l-2.5 long; leaf blades conduplicate, (0.5-)0.7-1.5(-2.1) in diameter, apex attenu-
ate to a sharp point, abaxially glabrous or scabrous, adaxially hirsute, with 7-9 veins and 7-9 adaxial ribs,
sclerenchyma in a continuous abaxial band and sometimes with adaxial fascicles at the veins, bulliform
cm
cells abscent. Inflorescence paniculate, 5-15(-20) long, lax and nodding, axis glabrous below and sca-
mm
brous distally, branches scabrous, a single branch at lowest node. Spikelets 9-14(-16) long, obovate
or broadly ellipsoid, with 4-6(-7) florets; glumes glabrous, scabrous or hispidulous, subulate to lanceolate,
mm mm
unawned with an awn up lower glumes 3-)7-10(-l with 1-3 upper
or to 1 long; (6. 1.5) long, veins;
mm mm
glumes (7.5-)8-ll(-13.8) long, with 3-5 veins; rachilla up to 1.5 long, unilaterally hispidulous
mm
lemmas
opposite to the floret; (7.5-)8-10(-12) long, lanceolate, scabrous, papillose or hirsute, with 5
mm
unawned awn
veins, apex usually bidentate, or usually with a short (0-)l-2(-2.9) long; paleas 6-7.5
mm
long, hispidulous between the veins and sometimes on the upper margins, veins with trichomes from
mm
the apex to about 3/4 to the base; anthers 1.5-4.5 long, mostly indehiscent; ovary apex glabrous.
Caryopses
not formed.
MEXICO.
Additional collections examined. Mexico: E slope of Nevado de Toluca, near gate to crater, 19°15'N 99°45'W, alpine solifluc-
&M.
tion 4000 m, 26 Sep 1997, Darbyshire Gonzalez-Ledesma 4849.
sites, ca.
S.J.
The open paniculate inflorescence of the F. xmiscella is similar in appearance to that of F. tolucensis, but with
fewer spikelets (usually less than 20 versus usually more than 20). The lower rachis internode is stiff or
somewhat lax, but not pendulous as in F. livida. The spikelets are obovate to broadly ellipsoid in F. xmiscella
with a length to width ratio usually 2 or less. In F. tolucensis the spikelets are usually lanceolate or narrowly
ellipsoid (occasionally broadly ellipsoid) with a length to width ratio usually 2.5 or greater (occasionally
as as The glumes are 3/4 as long as or about as long as the adjacent lemmas, whereas they are
little 1.5).
A
lemmas
usually 1/2 to 3/4 as long as the adjacent in F. tolucensis. comparison of additional characters is
2-27%
given in Table In lactophenol cotton blue preparations from the type collection, of pollen grains
2.
were evenly stained and/or regularly formed. This hybrid was identified and characterized by Gonzalez-
first
Ledesma
(1991).
836 Journal of the Botanical Research Institute of Texas
1(2)
Table 2. A comparison of chmclmtics of FesWca hephaestophilo, F. livldo, F. tolucensis d\](] their liybrids. Measurements in millimetres.
hephaestophila xgonzalez- livida xmiscella tolucensis
character F. F. F, F. F.
ledesmae
spikelet length 4.5-8.4 7-ll(-13) (9.4)10-17(21) 9-14(-16) (6.5-)8-14(-18)
glume
lower length 2.8-4.5(-5.5) (5.8-)6.5-8.5(-9) 9.2-1 5(-20) (6.3-)7-l 0(-l (2.7-)3.5-7.5(-8.6)
.5)
1
upper glume
length 3.5-6.3 (6.5-)7-9.5(-10) 9.4-1 7(-21) (7.5-)8-l (-1 (3.6-)4.5-8.5(-9.3)
3.8)
1
lemma
length 4-5.5(-6.2) 6.5-8.5(-9.5) 6.5-12.5 (7.5-)8-10(-12) (4.6-)5.5-8.5(-10)
anther length 2.2-3.5 (1-) 1.2-2 0.8-1.5 1.5-4.5 (2.6-)3-4.5(-5.2)
The following key species of Festuca in Mexico and Central America largely based on that by
to is
Alexeev (1984), but has been updated with additional information and recently described taxa. Although
frequently treated in a different genus, Festuca arundinacea Schreb. [Lolium arundinaceum (Schreb.) Darbysh.;
Schedonorus arundinaceus (Schreb.) Dumort.] included in the key and Table because of similarity to
is its
1,
and continued placement in Festuca by some authors. The inclusion of F. ovina L. is based on Godfrey 66649
report by Pohl (1980) for Costa Rica and accepted by Alexeev (1984). The specimen has not been examined
and remains
identity unclear.
its
KEY TO THE OF FESTUCA MEXICO AND CENTRAL AMERICA
SPECIES IN
mm
Leaf blades of shoots usually more than 2 wideTlat cross section, sometimes round the upper part
in in
1.
becoming when
(or involute or convolute dry), possessing distinct (wide) bulliform cells.
2. Margins of the blade-sheath junction with falcate auricles, more or less provided with cilia F. arundinacea
Margins of the blade-sheath junction lacking auricles, without
2. cilia.
mm
Ligulesofculm
leaves (1.3-)2-10(-l long.
3. 1)
mm mm
lemmas
4. Plants loosely caespitose; ligulesofculm leaves less than 3.5 long; less than 7 long,
apex
awnless.
entire,
mm mm mm
culm up lemmas 4-6
LIgules of leaves 2.5-3.5 long; leaf blades to 2 wide; long;
5.
plants of Mexico and Texas ligulata
F.
mm mm mm
1-4 lemmas
5. Ligulesofculm leaves less than 2.5 long; leaf blades wide; 5.7-6.8 long;
plants of Costa Rica and Panama herrerae
F.
l)mm
4. Plants densely caespitose; ligulesofculm leaves usual ly3-8(-l long (sometimes less especially
mm
in toncitoroensis): lemmas greater than 7 long, apex bidentate (sometimes entire), with an awn
F.
or mucro (sometimes absent) arising from between the teeth.
a
Apexof
ovaries densely hispid asperella
6. F.
Apexof
ovaries glabrous.
6.
mm
7. Ligulesofculm leaves 1.5-2.8 long; lemmas without an awn or at most with a short mucro
mm
than long tancitaroensis
ess 0.5
F.
mm mm
lemmas awn
Ligulesofculm leaves (1.3-)3-8(-l long; with an (0.5-)l-4 long.
7. 1)
mm mm
Leaf blades 3-5 wide; upper glume (5.5-)6-8.5 long _ lugens
8. stiff, F.
mm mm
Leaf blades 1.5-3.6(-6) wide; upper glume (3.8-)4-5.6(-6) long roblensis
8. lax, F.
mm
more
Ligulesofculm leaves not than long.
3. 1.5
mm
Lemmas
12-17.5
long.
9.
mm mm
10. Lower glumes (l-)2-6(-7.5) long; lemmas with 3-5 veins, awns 10-14(-16) long
breviglumis
F.
mm mm
10. Lower glumes (7.5-)8-9 long; lemmas with 5 veins, awns 1.5-3 long chiriquensis
F.
mm
Lemmas
3-9.5(-10) long.
9.
mm
Apex lemmas awns between
of bidentate, (0.3-)0.5-l long arising the teeth.
.8
1 1
.
mm
Lemmas
5.5-6.2 long, scabrous throughout the back; paleas scabrous along the keels
2.
1
mm
to the base; anthers 2.4-2.7 long; apex of ovaries densely hispid; plants of Panama
swallenii
F.
mm
Lemmas
12. 6.5-7 long, scabrous on the upper half; paleas scabrous along the keels on
mm
the upper third; anthers 3.5-4 long; apex of ovaries with a few hairs (1-4); plants of
Mexico bidenticulata
F.
Apex lemmas
of without teeth or awns.
1 1
.
mm mm
Lemmas
3-4.5 long, apex obtuse; anthers 1-1.3 long subverticillata
13. F.