LEPTOCHLOA (POACEAE: CHLORIDOIDEAE) IN COLOMBIA

2008·13.4 MB·

by  Neil Snow

LEPTOCHWA
(POACEAE: CHLORIDOIDEAE) COLOMBIA
IN
Snow
Neil Paul M. Peterson
Herbarium
Pacificum Department
ofBotany
Museum
Bishop Museum
National ofNatural
History
1525 Bernice Street Smithsonian
Institution
Honolulu, HI 968 U.S.A. Washington, DC 2001 3-70
1 7, 12, U.S.A.
[email protected]
[email protected]
Diego
Giraldo-Canas
Leptochloa P. Beauv., sensu lato (including Diplachne P. Beauv.) is a genus of approximately 32 annual or
perennial species (Snow 1997). The native range of the genus pantropical into warmer temperate
is regions,
with several species being weedy and widely distributed. Although Parodi McNeill
(1927), (1979), Phillips
(1982), Nicora and Rugolo de Agrasar (1987), and Nicora (1995) recognized Diplachne as a separate genus,
we McVaugh
agree with Clayton and Renvoize Nowack Snow
(1983), (1986), (1994), Renvoize (1998), and
number
1998a)
(1997, that the of florets, the size of the spikelets, shape of the caryopsis, arrangement of
on
spikelets the panicle branches secund or not secund), and other morphological
characters
(i.e., inter-
grade strongly and are unable to support generic separation (Snow 1997). Moreover, based on numerical
a
analysis of morphological characters, Phillips (1982) found that species placed in Diplachne and Leptochloa
overlapped one another
in a principal coordinates scatter plot. Although it is likely (next paragraph) that
some may
elements of Leptochloa need to be segregated in the future with further analyses, in our opinion
it
is unlikely that such a generic segregate would correspond closely to Diplachne as recognized by the authors
cited above. Thus time seems more
at this it appropriate to recognize Leptochloa in broad sense (Peterson
its
Snow
et 1997; 1997).
al.
The monophyly of Leptochloa sensu lato was not supported when tested cladistically with morphological
and anatomical data, depending on the number of outgroups included (Snow 1997). Moreover, monophyly
its
has not been tested in breadth using molecular data, and the relationship of Leptochloa with other genera
is
from (Columbus
far certain et al. 2007; Peterson et al. 1997, 2007). For example, in a restriction fragment
cpDNA New
analysis of using a few representatives of World genera (Duvall
et 1994), Leptochloa dubia
al. [L.
(Kunth) Nees] was member common
a of a basal clade, sharing a ancestor with Scleropogon Phil, Dasyochloa
Willd. ex Rydb., Munroa Torr., and Erioneuron Nash. In a strict consensus tree with bootstrap analysis, species
common
of Leptochloa did not form a particularly strong clade with the other genera, and instead shared a
ancestor in a clade that included the Muhlenbergiinae, Munroinae, Scleropogon, Sporobolus R. Br., Eleusine
&
&
Roem. Tripogon Roem. Schult., and Eustachys Desv. (Duvall et al. 1994). In a
Gaertn., Tridens Schult.,
phylogenetic study of Chloridoideae based on matK sequences, Leptochloa (L. dubia) formed a clade with
&
&
Other
Coelachyrum Hochst. Nees, and Astrebla Muell. emerged as sister to these (Hilu Alice 2001).
F.
Cynodon
genera in the C clade of Hilu and Alice (2001) included Brachyachne (Benth.,) Stapf, Chloris Sw.,
x
Dinebra Enteropogon Nees, Eustachys Desv., Lepturus R. Br., Lintonia Stapf, Microchloa R.
Rich., Jacq., Eleusine,
&
and Fourn. Benth. In another phylogenetic study
Oxychloris Lazarides, Tetrapogon Desf., Trichloris E.
Br.,
on combined trnL-F and ITS sequences, the placement of species of Lep-
Chloridoideae based analysis of
of
tochloa dubia, L.jusca (L.) Kunth, and L. panicea (Retz.) Ohwi] in separate clades suggests a polyphyletic
[L.
formed
origin (Columbus et 2007). In a phylogenetic analysis of rpsl6 sequences, Leptochloa dubia a clade
al.
waxy
whereas based on analysis of sequences, Leptochloa
with Eleusine coracana (L.) Gaertn.], in a tree
[E.
and
formed a clade with Eleusine coracana and Dactyloctenium aegyptium (L.) Willd. D. radulans (R. Br.) P.
&
Beauv. (Ingram Doyle 2007). In summary, the monophyly of Leptochloa has not been corroborated with
(Columbus
with other genera remain obscure
molecular and phylogenetic relationships of Leptochloa
data,
genus
et al. 2007, Peterson et al. 2007). For these reasons Peterson et al. (2007) treated the as incertae sedis
within the tribe Cynodonteae.
New which
Leptochloa represented by 17 species in the World (13 of these native), six of occur in
is
Our taxonomic treatment contains keys
Colombia (Penaloza-Jimenez 2002; Peterson et 2001, 2007).
et al. al.
and synonymies. Only
determining the species, descriptions, distributions, specimens studied, illustrations,
for
Snow
synonymy Peterson
synonyms used frequently in Colombian literature are given. For further see (1997), et
COAH,
and Soreng This study based on the examination of herbarium specimens from
(2001), et (2008). is
al. al.
CAUP, COL, HUA, MO, and US, including the type specimens of most species studied. The present study aims
Program and
to contribute to the knowledge of the Colombian grasses by collaborating with the Biodiversity
Colombian
Flora Inventories.
Leptochloa Beauv, Ess. AgrostOgr. 71. 1812. Type: Leptochloa virgata (L.) P. Beauv.
P.
and
and rhizomes but sometimes geniculate root-
Plants annual or perennial; caespitose, lacking stolons
cm
ing the lower nodes in mesic habitats. Flowering culms 30-150 tall, ascending to erect, glabrous to
at
than internodes with
sometimes pilose, arising from fibrous roots. Leaves cauline; sheaths longer or shorter
smooth margins; ligules a membrane or a ciliate membrane; blades narrowly lanceolate to linear, flat, often
primary branches exserted lower
inrolled on drying, not pungent. Inflorescence a panicle of spicate (or
main main primary
branches occasionally inserted proximally) along an elongated axis; axis scabrous;
main
branches spaced or sometimes subdigitate, ascending to spreading from axis, terminating in a spike-
glabrous or scabrous. Cleistogamous spikelets absent or present in axils of lower sheaths (in L. dubia or
let;
lemma
above glumes, and palea falling as a unit; callus
rarely in L.jusca subsp./asricularis). Disarticulation
glabrous sparsely sericeous. Spikelets solitary, laterally compressed or terete, subsessile to shortly (<2
to
mm) glumes than unequal, smooth,
pedicellate, distant but often imbricate, often secund; shorter spikelets,
glumes upper glumes shorter than lower lemma, 1-3-veined,
glabrous or slightly scabrous; lower 1-veined;
unawned; pronounced between glabrous; florets 2-13 per spikelet, sterile florets often pres-
rachilla florets,
lemma
3-veined
above (and uppermost often reduced to small, awnless rudiment);
ent fertile florets floret
and sometimes
membranous, smooth, glabrous or hairy along veins
(rarely 4-5-veined in L. dubia at base),
between apex emarginate or lobed, awnless, mucronate, or awned; paleas glabrous to sericeous,
veins, entire,
unawned, membranous, margins not enfolding fruit, smooth; lodicules truncate; stamens 2 or 3; anthers
(sometimes weakly caryopses dorsiven-
yellow or reddish-purple; stigmas 2. Fruit with adnate pericarp so);
compressed compressed (Snow 1998a). Base chromosome number of x = 10.
or laterally
trally
was
Comments.— and Diplachne were established by Palisot de Beauvois (1812). Leptochloa
Leptochloa
Kunth
based on three species, while Diplachne was based on D. fascicularis (Lam.) P. Beauv. [= L.jusca (L.)
Snow
et Leptochloa Colombia
al., in 863
subsp. fascicularis (Lam.) N. Snow]. Leptochloa was later lectotypified with L. virgata (L.) Beauv. by Nash
P.
which was Nominum
(1913), ineffective according Index Genericorum example
to Art. 10.5 In addition,
6.
both genera were placed in the same "cohors," which suggested that Palisot de Beauvois regarded them
as
more
or less closely related. In his "Tabula Methodica" he mentioned that the lemmas of Diplachne were shortly
awned, whereas those of Leptochloa were said to be awnless. However, this feature varies considerably and
lemma
the of Leptochloa can be entire, emarginate, lobed, awned, mucronate, or unawned. The micromor-
lemma
phological characters of the vary little in Leptochloa (Snow 1996), and with few exceptions, cork cells
are present, silica cells are absent, chloridoid bicellular microhairs are present, prickles are present, and
macrohairs are present. However, the occurrence of papillae on long cells and short cells is more variable,
may
suggesting their presence or absence be phylogenetically informative within the genus (Snow
1996).
—
Ecology and geographic distribution. The native range of Leptochloa nearly worldwide in warm-temperate
is
to tropical regions. Its ecological distribution mostly includes semi-open vegetation such as grasslands. The
most grow
species frequently in periodically disturbed or seasonally saturated areas such as riparian cor-
ephemeral impoundments,
ridors, pools, or although
artificial L. dubia generally prefers well drained
soils.
All widespread annual species are considered weedy in agricultural situations (Snow 1997) and some have
&
become
established on continents far beyond their native range (Snow Simon 1999; Snow 2004).
KEY TO THE OF LEPTOCHLOA COLOMBIA
SPECIES
IN
Sheaths sparsely to moderately
pilose,
th<
1
.
Sheaths glabrous to sparsely the ha
hairy,
1
.
membranous
Ligules and neither
2.
cili
membranous
Ligules
.
on
florets slightly diverging from anthe
rachilla at
s;
Plants annual; 2.2-3.8
ligules long.
Culms more
round
5. or less in cross section; panicle branches
rr
mm
mm
long; anthers 0.6-0.8 long
-C). ChlorisdubiaKumhJ
mm
Perennials, mostly erect or infrequently decumbent or sprawling. Culms (5-)30-110 cm 1.0-4.5
tall,
wide, unbranched or only as tillers from very base, round or flattened below; nodes glabrous, internodes
cm
3-11
long, herbaceous, solid (or occasionally hollow by virtue of aging). Leaf sheaths longer or shorter
than
internodes, sparsely pilose, especially below, and occasionally pilose (sometimes densely near the
so)
collar, the hairs occasionally from papillose bases, the margins glabrous or somewhat pilose; collars green
mm
or tan; ligules mostly 1.0-1.5 long, membranous, truncate, blades (2-)8-35 cm
ciliate apically; long,
mm
2-8
wide, mostly somewhat
linear or lanceolate, scabrous above at base or with a sparse covering of
pilose hairs, glabrous to minutely scabrous below, but drying involute, midvein mostly prominent
flat or
sometimes
two
not. Panicles of types, the apical ones generally exserted at maturity and the lateral ones
completely hidden in lower leaf sheaths; apical panicles 10-45 cm long, (2-)3-25 cm wide; the branches
cm
(2-)5-15, (1.5-)3-19
long, alternate or infrequently subdigitate, ascending to reflexed, often somewhat
mm
lax, minutely scabrous, the branch axils pilose or merely scabrous. Spikelets 4.0-12.0 long, imbricate
of the Botanical Research Institute of Texas 2(2)
Snow
et Leptochloa Colombia
al., in
mostly
to distant, sessile; florets 4-13; callus glabrous or with a few short hairs;
1
mm
membranous,
long, narrowly
triangular or ovate, scabrous along midvi
mm
acute; upper glumes 3.3-6.0 membranous,
long, ovate to lanceolate, scabrous on midvein (and some-
mm
times with or 2 additional veins and on lemmas
1 at least basally) papillate edges, acute; 3.5-5.0
long,
membranous,
ovate to obovate or widely obovate, light brown, bronze, light to very dark green, the lateral
veins usually prominent but sometimes not so, sericeous at least along lower portions of lateral veins and
sometimes on midvein and between
apex
veins, the usually broadly awn-
bifid, acute, obtuse, or truncate,
less or mucronate; paleas subequal to lemma, lanceolate, membranous above but somewhat
cartilaginous
near base, distinctly ciliate on edges, sometimes sericeous between veins, apex acute; stamens anthers
3;
mm
mm mm
(0.3-)1.0-1.6 long, yellow. Caryopses 1.5-2.3 long, 0.9-1.0 wide, narrowly
elliptic, elliptic or
very widely obovate
in hilar profile, depressed obovate in transverse section, with a broad, shallow groove
on
smooth, brown;
hilar side, pericarp weakly adnate endosperm.
the
to
USA
Distribution and habitat.—Native in the from Arizona to Oklahoma and Texas, southern Florida,
common
in Mexico, sporadically in the Caribbean and in Mesoamerica through more common
Bolivia, again
from Bolivia and Chile through Paraguay, Uruguay, and southern and much
Brazil of Argentina; in a variety
and
of soil vegetation types, but most frequently on well-drained slopes, 100-2600 m, but occasionally
to
m
3150 in Peruvian and Bolivian Andes.
Syn. PI. Glumac. 1:247. 1855. Type: PALESTINE: F. Hasselquist s.n. (lectotype: LINN 92.21!, designated by Phillips, Fl. Trop. East
Gram.
Afr. 2:281. 1974).
Annuals, ascending sometimes and Culms cm
to erect, geniculate rooting lower nodes. 130 (when
at to
tall
mm
1-8
erect); wide, branched or unbranched; nodes glabrous; internodes (0.5-)3-26 cm
long, hollow,
herbaceous sometimes
or firm. Leaf sheaths longer or shorter than the internodes, glabrous on and
sides
mm
margins; mostly brown 5-8
collars light or green; ligules long, hyaline, apically attenuate but often
mm
becoming lacerated due to mechanical damage; blades (3-)5-50 cm 2-6
long, wide,
linear, gla-
flat
brous to somewhat scabrous above and below. Panicles 15-150 cm mostly 2-30 cm
long, wide,
partially
included at base to completely exserted; the branches (1.5-)3-20 cm long, (3-)5-35 per panicle, alternate,
sometimes
reflexed or steeply but mostly somewhat
erect ascending, minutely scabrous, the branch
stiff,
mm
axils glabrous. Spikelets 5-12(-14) more
long, short pedicellate, or less secund, sometimes distant near
base of branches but overlapping near branch
tips; florets (3-)6-12; callus glabrous or hairy; lower glumes
mm
membranous,
1.0-3.5(-4.9)
long, lanceolate to ovate, usually scabrous on the midvein, broadly acute
mm
to acute, awnless or infrequently shortly awned; upper glumes 1.8-5.5
long, elliptic, usually ovate or
widely sometimes
ovate, obovate, scabrous on midvein, obtuse
(rarely) or acute at apex, rarely short-awned;
mm
lemmas
2.3-6.0 membranous,
long,
elliptic, ovate, or lanceolate, the lateral veins distinct and often
more
slightly excurrent, or less sericeous on lateral veins and the midvein; apex truncate, obtuse, to acute
mm
or acuminate and sometimes awn
awnless, mucronate, awned,
bifid, or the to 3.5 long; paleas subequal
or slightly exceeding lemma, more or less sericeous on veins; apex acute or obtuse; stamens 2 or mostly
1,
mm
mm
mm
anthers 0.2-2.7 Caryopses
3; long. 1.0-2.4 long, 0.7-1.2 wide, elliptic, ovate, or obovate in
hilar profile, transversely elliptic to depressed obovate in transverse section, hilar groove lacking, smooth
sometimes
or slightly rugose, brown; pericarp weakly adnate the endosperm.
to
common
Distribution.—Widespread and abundant warm-temperate and
to in between
tropical areas,
New
approximately 49°N and 40°S in the World and 40°N and 42°S in Old World; mostly below 2000 m.
—
Comments.
Populations of the Leptochloa fusca complex often appear morphologically
distinct in
lo-
.
Journal of the Botanical Research Institute of Texas 2(2)
866
and
names been forms throughout the Americas, Africa,
and dozens of have applied to regional
cal areas,
Since morphological characters intergrade when considered globally most local variants do
Australia. all
not merit taxonomic recognition (Snow 1997). However, herbarium work and multivariate statistical studies
and support
(Snow, unpubl.) based on eleven population samples (n = 30) from America, Africa, Australia,
recognition of four subspecies. The subspecies, which are usually easy to distinguish, are: L.jusca subsp.
the
New
polymorphic paleotropical taxon adventive in a few areas in the World (Nicora 1995); L.jusca
fusca, a
known much and Simon
subsp. muelkri (Benth.) N. Snow, from of the interior of Australia (Sharp 2002);
and
fusca subsp. uninervia, native to the neotropics but adventive elsewhere; L. fusca 3sp. fascicularis,
L.
New
native to the temperate and tropical regions of the World.
COLOMBIA
KEY TO SUBSPECIES OF LEPTOCHLOA FUSCA IN
panicle branches often inserted upper sheath; uppermost leaf blade lengtl usu-
in
ng length of panicle; leaf sheaths sometimes mottled with anthocyanin pigments; len
Lowermost panicle branches generally exserted from sheath; uppermost leaf blade length generally not ex
.
ceeding terminal panicle; leaf sheaths only rarely mottled with anthocyanin pigments; lemmas smoky white o
times dark green or plumbeous, but usually
n<
mm
Culms (3.5-)15-130 cm l-5(-8) wide, often branching, round; nodes
Annuals, ascending
to erect. tall,
3-18 cm Leaf sheaths mostly longer than the internodes,
herbaceous, hollow.
glabrous; internodes long,
mm
cm
3-45
on and margins; green or brown; ligules 5-7 long, hyaline; blades
glabrous sides collar light
mm
when
becoming
long, 2.5-7 wide, linear, usually sparsely scabrous above and below, flat but involute
cm
cm
included
midvein prominent. Panicles (1.5-)10-72 long, (l-)4-22 wide, generally partially
dry,
cm
ascending,
below; the branches 3-35, (0.5-)3-22 long, alternate, erect,
5-12 mi
or slightly flexuous, minutely scabrous, the axils glabrous. Spikelets
mm
lower g"
cate, pedicels less than 1 long; florets 6-12; callus glabrous;
lanceolate or somewhat asymmetric, scabrous on midvein, acute to aris
mm
membranous, scabro
upper glumes 2.5-5.0 long, elliptic to ovate,
mm
lemmas membranous,
short-awned; 2.5-5 long, lanceolate, light to
white, the lateral veins pronounced and extending to edges often as sn
veins and often midvein, glabrous between veins; apex acute to
lateral
:
lemma,
awns subequal sericeou<
3.5 long; paleas generally to elliptic,
to
mm
mm
stamens anthers 0.2-0.5 long, yellow. Caryopses 1-2 long, 0.
3;
groove smooth, brown; peric
transversely in transverse section, hilar lacking,
in hilar profile, elliptic
weakly adnate the endosperm.
to
Washing
and habitat—Massachusetts (USA) and southern Ontario (Canada) west to
Distribution
40° open mesic brackish marshes along the east
(USA) and south about latitude S in Argentina; areas,
to
from 1850
US seaboard, agricultural lands, ruderal sites along roads, and saline flats. Elevation sea level to
Specimens examined. COLOMBIA. La Guajira: Costa del Caribe, llanura literal arenosa y arida entre Mayapo y El Pajaro, 29 Jan 1!
Dugand 6667 (COL, US).
A.
Novon D-F).
2b. Leptochloa fusca subsp. uninervia Presl) N. Snow, 8:79. 1998b. (Fig. 2, Megasta
(J.
Annuals or occasionally weakly perennial in regions lacking erect or ascending. Culms (15-)25-110
frosts,
mm
cm
2-5 cm
tall, wide, often branching, round; nodes glabrous; internodes 2-11 long, herbaceous, hollow.
Leaf sheaths longer or shorter than the internodes, often flattened below, glabrous on sides and margins;
mm
mm
5-8 cm
collars mostly tan or green; ligules long, hyaline; blades (2-)5-37 long, 2.0-5.5 wide,
linear,
usually densely scabrous above, sparsely to densely scabrous below, flat but becoming involute when dry,
868
cm cm
midvein prominent. Panicles 10-57 long, (0.5-)3-18 wide, usually exserted; the branches (3-)10-60,
cm
(0.3-)2-ll long, the branches mostly alternate, ascending to erect, stiff or slightly flexuous, minutely
mm
scabrous, the axils glabrous. Spikelets 5-10 long, rarely distant to normally imbricate (sometimes tightly
mm
so), pedicels mostly less than 1 long; florets (3-)6-10; callus sparsely sericeous; lower glumes 1.0-2.6
mm
long, membranous, narrowly triangular, lanceolate, or ovate, glabrous or scabrous on midvein, acute to
mm
aristate or mucronate; upper glumes 1.8-2.8 long, membranous, obovate to widely ovate, glabrous or
mm
lemmas membranous,
scabrous on midvein, obtuse, acute, or rarely mucronate; 2.0-3.6 long, ovate or
elliptic, light brown to very dark green or somewhat plumbeous, lateral veins more or less prominent and
generally extending to edges, sparsely sericeous below on lateral veins and often midvein, glabrous between
veins; apex broadly acute, more commonly obtuse to truncate, sometimes bifid or mucronate; paleas subequal
or slightly longer than lemma, membranous, elliptic, sericeous along veins; apex obtuse; stamens 3; anthers
mm mm mm
0.4-1.0 long, yellow. Caryopses 1.0-1.5 long, 0.7-0.8 wide, elliptic, ovate, or obovate in hilar
smooth brown;
transversely in transverse section, hilar groove lacking, or slightly rugose,
profile, elliptic
pericarp weakly adnate endosperm.
to
—
New
Distribution and habitat. In the World mostly south of latitude 37°N, south to Argentina, occa-
sionally adventive in Old World (Snow and Simon 1999); open mesic areas, agricultural lands, saline flats,
mangrove swamps. from 1200 m.
Elevation sea level to
is
Specimens examined. COLOMBIA. Atlantico: Entre Palmar de Varela y Ponedera, bosques xerofiticos, 10 m, 27 Ago 1960, A. Dugand
5304 (COL, US). Magdalena: Cienaga, alrededores de Aguacoca, 20 m, 21 Feb 1959, R. Romero-Castaneda 7268 (COL, US).
Novon
3. Leptochloa panicea subsp. brachiata (Steud.) N. Snow, 8:79. 1998b. (Fig. 3, A-E). Leptochloabmchiata
GUADALOUPE US
Steud., Syn. Glumac, 209. 1854. Type: [French Republic]: Duchassaing s.n. (holotype: P!; fragm.!).
Pi.
SOUTH
Pers., Syn Pi. 1: 87. 1805. Leptochloa filiformis (Pers.) P Beauv., Ess. Agrostogr.: 71, 163, 166. 1812. Type:
lis
mm
cm
Annuals, ascending Culms (10-)30-150 mostly than 5 wide, frequently branched;
to erect. tall, less
cm
nodes glabrous; internodes mostly 5-30 long, hollow, herbaceous or sometimes firm. Leaf sheaths lon-
ger or shorter than the internodes, sparsely to moderately pilose (hairs with papillose bases); collars often
mm mm
cm
magenta; ligules 1.0-3.2 long, membranous but erose apically; blades 6-25 long, 2-21 wide,
cm cm
glabrous sparsely pilose on both surfaces. Panicles 8-30 long, usually 5-35 wide,
linear, flat, to
cm
occasionally partially included at base; the branches (l-)3-19 long, (3-)10-100 per panicle, alternate,
ascending (mostly) to somewhat reflexed apically (but otherwise firm), minutely scabrous, the branch axils
mm
glabrous. Spikelets 2-4 long, short pedicellate, more or less secund, sometimes distant near base of
mm
branches but overlapping near branch tips; florets 2-5(-6); callus glabrous; lower glumes 1.6-4 long,
mm
membranous, lanceolate, usually scabrous on the midvein, acute, awnless; upper glumes 1.6-3.6 long,
mm
lemmas membranous, more on
lanceolate, awnless; 1.3-1.7 long, lanceolate, or less sericeous lateral
veins and the midvein; apex acute, awnless; paleas subequal to lemma; apex acute or obtuse; stamens 3;
mm mm mm
more rounded
anthers 0.2-0.3 long. Caryopses 0.9-1.2 long, 0.5-0.6 wide, or less in hilar
profile, widely depressed obovate to obdeltoid in transverse section, hilar groove narrow and shallow, smooth
or sometimes slightly rugose, brown to reddish; pericarp adnate to the endosperm.
—
Distribution and habitat. Southern third of United States through Mesoamerica and the West Indies
to southern Brazil and Argentina; disturbed, mesic, and agricultural sites, to ca. 2800 m.
—
much warm
Comments. Leptochloa panicea a polymorphic species occurring throughout of the
is
temperate and tropical regions, and comprised of three subspecies (Snow 1997, 1998a). Snow and Davidse
is
New
(1993) reported that the name then in use for the widespread World taxon, L. filiformis (Lam.) P. Beauv,
homonym
was an should be replaced by mucronata (Michx.) Kunth. Although not
illegitimate later that L.
New
the do Nowack (1994, 1995) recently placed World specimens as a subspecies of the oth-
first to so,
erwise Old World species panicea, and made the new combination L. panicea subsp. mucronata. Included
L.
in Nowack's concept of L. panicea subsp. mucronata were two taxa formerly recognized as L. filiformis vars.
Snow
and attenuata, which (1997, 1998b) treated (respectively) as L. panicea subsp. brachiata (Steud.)
filiformis
Snow
et Leptochloa Colombia
al., in
A. Habit. B. Inflorescence. C. Portion of the leaf sheath with a covering of papillose-based
e;. I
870
N. Snow and panicea subsp. mucronata (Michx.) N. Snow. The much more widespread taxon, referred to
L.
&
new name
(Snow was
earlier as L.filiformis or L. mucronata Davidse, 1993), given the L. panicea subsp.
(Snow
brachiata 1998b).
Drawing on and
experience exa
field
eluded that the phenetic variation sufficiently c
is
L. panicea subsp. brachiata is present in Colombia.
—
Vernacular name. Pasto paja-mona (Valle del Cauca).
COLOMBIA. km
Specimens examined. Antioquia: Mun. Necocli, 42 carret
mm
cm
Annuals, often geniculate below but generally Culms (7-)45-110 1-7 wide, branch-
erect. tall,
cm
ing (sometimes profusely), round; nodes glabrous; internodes (l-)4-10 long, herbaceous, hollow.
somewhat
Leaf sheaths generally longer than the corresponding internodes, flatted below, glabrous, the
margins sometimes very sparsely ciliate along the lower half; collars sometimes magenta; ligules 2.2-3.8
mm mm
long, membranous, truncate, somewhat erose apically; blades 4-20 cm long, mostly 4-8 wide,
and
linear or the shorter ones lanceolate, glabrous to minutely scabrous above below. Panicles (l-)20-35
cm cm cm
long, (3-)4-12 wide, generally exserted; the branches (20-)40-90, 2.5-7 long, alternate, mostly
mm
4-5
ascending, to weakly flexuous, minutely scabrous, the axils glabrous. Spikelets long, generally
stiff
mm
somewhat imbricate, pedicles 1-2 long; florets (4-)5 or 6(-7); callus glabrous; lower glumes 0.9-1.9
mm
long, membranous, narrowly lanceolate to lanceolate or sometimes falcate, minutely scabrous on the
mm
midvein, acute; upper glumes 1.8-2.3 long, membranous, ovate, minutely scabrous on the midvein,
mm
acute to obtuse; lemmas 2.4-3.0 long, membranous, narrowly elliptic to ovate, tan, maroon, or green,
at base of lateral veins and/or midvein; apex acute to broadly acute, awnless or mucronate; paleas subequal
to ca. 2/3 as long as the lemma, membranous, ovate to elliptic, glabrous throughout; apex obtuse; stamens
mm mm mm
maroon
anthers 0.6-0.8 long, or yellow. Caryopses 1.1-1.4 long, 0.7 wide, elliptic in hilar
3;