Old World species of Trichanthecium (Poaceae: Panicoideae: Paniceae) including a new species from the Democratic Republic of Congo
Author
Zuloaga, Fernando Omar
Instituto de Botánica Darwinion, ANCEFN-CONICET, Labardén 200, B 1642 HYD San Isidro, Buenos Aires, Argentina
Author
Aliscioni, Sandra
Instituto de Botánica Darwinion, ANCEFN-CONICET, Labardén 200, B 1642 HYD San Isidro, Buenos Aires, Argentina
Author
Delfini, Carolina
Instituto de Botánica Darwinion, ANCEFN-CONICET, Labardén 200, B 1642 HYD San Isidro, Buenos Aires, Argentina
Author
Salariato, Diego Leonel
Instituto de Botánica Darwinion, ANCEFN-CONICET, Labardén 200, B 1642 HYD San Isidro, Buenos Aires, Argentina
text
Phytotaxa
2024
2024-05-06
646
3
230
264
http://dx.doi.org/10.11646/phytotaxa.646.3.2
journal article
10.11646/phytotaxa.646.3.2
1179-3163
13215433
4.
Trichanthecium chionachne
(Mez) Zuloaga
,
comb. nov
.
Panicum chionachne
Mez (1921: 185)
.
Lectotype
(
here designated
):—
TANZANIA
.
Rungwe
District,
Kymbila
,
1600 m
,
15 May 1912
,
A. Stolz
1270
(
M
[
0103866
] image!,
isolectotypes
BR
[0000008760661!],
G
[00022446!],
JE
[00006127] image!,
K
[000282487!],
L
[1294047] image!,
S
–G-[4483] image!,
U
![0257877] image,
US
[00148350!] [fragment ex M], US [00731052!],
W
[19160007804!],
WAG
[0001524] image!)
.
Fig. 5
Annual or short lived, not tufted perennial; culms slender
35–90 cm
long, decumbent and branching at the lower and middle nodes; internodes cylindrical,
3–12 cm
long, hollow, glabrous; nodes compressed, pale, glabrous.
Sheaths
striate, 3–10(–15) cm long, usually shorter than the internodes, sparsely hispid to glabrous.
Ligule
membranous, laciniate at the apex,
0.6–0.7 mm
long, hyaline, with long hairs beneath at the base of the blade.
Blades
lanceolate, 5–10(–16) ×
0.5–1 cm
, rounded toward the base and then narrowed into a short and pilose pseudopetiole, pseudopetiole pilose, acuminate, glabrous or pilose, the margins scabrous.
Inflorescence
a terminal, lax and exserted panicle, 10–20 ×
6–20 cm
; peduncle cylindrical,
15–25 cm
long, hispid to glabrous, pulvini hispid or glabrous; first-order branches alternate, divergent, axis of the branches glabrous, spikelets solitary on flexuous, claviform pedicels
1–5 mm
long.
Spikelets
ovoid, 2.1–2.5 ×
0.8–0.9 mm
, acuminate, greenish and tinged with purple; lower glume lanceolate,
2–2.2 mm
long, 4/5 to as long as the spikelet, 3-nerved, acute, membranous, glabrous; upper glume ovate, 5(–7)-nerved, membranous, acute or acuminate, glabrous; lower lemma glumiform, 5-nerved, membranous, acute, glabrous; lower palea narrowly elliptic-ovate, 1.4–1.6(–2) ×
0.4–0.6 mm
, hyaline, glabrous; lower flower staminate or neuter.
Upper anthecium
ovoid, 1.5–1.9 ×
0.7–0.9 mm
, indurate, pale, glabrous, smooth, shiny; upper lemma 5-nerved.
Caryopsis
narrowly ovoid, 1.2 ×
0.6 mm
; hilum punctiform, embryo 1/3 the length of the caryopsis.
Distribution and habitat:
—This species is commonly found in east tropical Africa(
Burundi
,
Rwanda
,
Democratic Republic of Congo
,
Sudan
,
Kenya
,
Tanzania
,
Uganda
.
Malawi
, and
Zambia
) in shaded forest habitats, from
1000–3000 m
elevation.
Typification:
—The
holotype
of
Panicum chionachne
at
B
was destroyed. An
isotype
at
M
is here designated as
lectotype
; it was identified by Mez and consists of a full specimen that agrees with the protologue.
Notes:
—This species is morphologically related, and perhaps conspecific, with
Trichanthecium hochstetteri
, the latter differing by having spikelets usually sparsely pubescent, oblong in outline.
Brown (1977)
reported that this is a non-Kranz species.
FIGURE 5
.
Trichanthecium chionachne
.
A
. Habit.
B
. Ligular region.
C
. Detail of a branch of the inflorescence.
D
. Spikelet, lateral view.
E
. Lower glume.
F
. Lower palea with anthers.
G
. Upper anthecium, dorsal view.
H
. Upper anthecium, ventral view.
I
. Upper palea, lodicules and caryopsis.
J
. Caryopsis, hilum view. (
Wiehe N/363
US).
Representative specimens examined:
—
BURUNDI
.
Siguvyaye
(
Bururi
),
1 June 1979
,
Ndabaneze
638
(
BR
).
DEMOCRATIC REPUBLIC OF CONGO
.
Nioka
,
10 March 1956
,
Froment
10
(
BR
).
MALAWI
.
Zamba Plateau
,
23 November 1949
,
Wiehe
N/363
(
P
,
US
)
;
Mlanje Mountain
,
Likabula valley
,
Wiehe
N/358
(
US
)
;
banks of
Mulungusi
stream,
Zomba
,
Wiehe
N/611
(
US
).
TANZANIA
.
Mpanda District
:
12 km
N of Uzondo Camp
,
5 May 2008
,
Bidgood
et al. 6667
(
K
,
P
)
;
Uzondo Plateau
,
17 April 2006
,
Bidgood
et al. 5581
(
K
,
MO
,
P
)
;
Mufindi
,
Kigogo river
valley,
Renvoize
&
Abdallah
1903
(
K
,
MO
)
;
Nyassa-Hochland
,
Station Kyimbila
,
Stolz
1374
(
JE
).
UGANDA
.
Kigezi
,
Kachwekano Farm
,
Purseglove
3476
(
K
)
;
Mubende
,
Thomas
4123
(
K
,
US
).
ZAMBIA
.
Muchinga
.
Mpika District
:
Mutinondo Wilderness Area
, western end of
Airstrip
,
9 May 1916
,
Bidgood
et al. 8727
(
K
,
P
)
.