Three new species of Senecio (Compositae: Senecioneae) from the Alto Marañón, Huánuco region, Central Peru
Author
Montesinos-Tubée, Daniel B.
Naturalis Biodiversity Centre, Botany Section, National Herbarium of The Netherlands, Herbarium Vadense. Darwinweg 2, 2333 CR Leiden, The Netherlands. & Instituto Científico Michael Owen Dillon, Av. Jorge Chávez 610, Cercado, Arequipa, Perú. & Instituto de Ciencia y Gestión Ambiental de la Universidad Nacional de San Agustín de Arequipa. Calle San Agustín 108, Arequipa- Perú.
Author
Pino, Guillermo
Museo de Historia Natural, Universidad Nacional Mayor de San Marcos, Lima, Perú.
Author
Zárate-Gómez, Ricardo
Instituto de Investigaciones de la Amazonía Peruana / Programa de Investigación en Cambio Climático Desarrollo Territorial y Ambiente (PROTERRA). Dirección: Av. Quiñones km 2.5, San Juan Bautista, Maynas, Loreto, Perú.
text
Phytotaxa
2018
2018-04-17
347
3
213
223
http://dx.doi.org/10.11646/phytotaxa.347.3.2
journal article
302418
10.11646/phytotaxa.347.3.2
99b44eec-eac8-4c7d-981c-daa7fb148d69
1179-3163
13708113
2.
Senecio inghamii
Montesinos
,
sp. nov.
(
Fig. 4A–F
,
5A–D
)
Type
:—
PERU
.
Huánuco
: Huacaybamba, Huacaybamba, Copuma Bridge, arid scrublands with cacti,
09°04’25” S
,
76°56’26” W
,
2156 m
,
13 May 2017
,
D. Montesinos 5578
(
Holotype
HSP
,
isotypes
HUSA
,
CUZ
,
HUT
,
F
,
B
,
K
,
MO
).
Diagnosis.
Differs from similar Andean
Senecio
species
by its short-sized, oblanceolate-ovate to rhombic-quadrate leaves with a unique serrate-quadrate dentation, the upper surface being lustrous and glossy and lower surface densely covered with whitish lanuginose pubescence, capitules bear trilobulated ray florets and achenes copiously covered by fimbriate hairs.
Description.
Habit:
Shrubby annual plant, ramified from the base, rarely prostrate,
25–35 cm
tall.
Stems
erect, partly covered with plicate arachnoid pubescence, consistent on leaf nodes, about
5–8 mm
wide in the lower section and
2 mm
wide in the upper stems, bark smooth, dark red to pale brown with age, bearing 14–16 pale brown ribs.
Trichomes
lanuginose, arachnoid, ca.
0.1–0.2 mm
thick.
Leaves:
basal leaves absent. Cauline leaves alternate,
0.6–2.5 cm
long,
0.5–1.6 cm
wide, subcoriaceous, oblanceolate-ovate to rhombic-quadrate with maturity; upper surface lustrous, glossy, yellowish dark green to brown and rugose with maturity, glabrous except in the midrib, cuticle composed of translucid glands; lower surface pale green turning pale brown with age, densely covered with a thin indumentum of whitish lanuginose hairs (layer of
0.4 mm
thick) turning greyish white with age; margin glabrous, serrate-quadrate, with 2–4 acute mucronate lobes (
0.4–2.2 mm
long); apex acuminate, mucronate; base attenuate to oblique; central nerve
0.1–0.5 mm
width, somewhat inconspicuous on the upper surface, covered by a thin narrow layer of white pubescence (less thick to gradually absent in secondary veins) of about
0.1–0.6 mm
thick, midrib prominent at the base on the lower surface with gradually fewer cover of pubescence towards the apex; petioles
2–15 mm
long, conspicuously winged.
Synflorescence
solitary, with short calycular bracts, linear,
4–9 mm
long, pubescent on the lower surface and the apex. Pedicels
4–6 cm
long, about
1 mm
thick, scarcely covered with whitish pubescence.
Capitules
radiate,
2.2–2.6 cm
in diam.,
1.5–2 cm
long;
involucre
cylindrical,
5–7.5 mm
in diam.,
6–10 mm
long. Receptacles ca.
3.4–4.5 mm
wide,
1 mm
high, convex, glandular, glossy brown. Phyllaries 10–12,
6–10 mm
long,
1–2.1 mm
wide, fimbriate, oblong, acuminate, upper surface scarcely pubescent, hairs
0.5–1 mm
long, glabrous or pubescent along margins, apex acute-acuminate (
1–1.3 mm
long) bearing a tuft of dense white multicellular hairs,
0.3–0.6 mm
long. Ray florets female, 9–11,
15–18 mm
long,
2.5–3.2 mm
wide, oblong, trilobulated, glabrous, bright yellow, usually curved towards the apex, lamina disposing 4–5 parallel nerves, pale yellow,
0.1–0.2 mm
width; floret
4–5 mm
long, style trifurcated, curved,
6–8 mm
long, and covered by minute glands at the tip. Disc florets hermaphrodite, ca. 30–40,
6–10 mm
long, corolla dark yellow, lobes 5, acute, ca.
1 mm
long; tube
3–5 mm
long. Anthers crowned by an oblong, membranous appendage. Style
6–10 mm
long, slender, bifurcated, thickened at the base; style branches papillose at the tip.
Achenes
heteromorphic, linear, rarely oblong, copiously covered by fimbriate hairs.
Achenes:
Ray achenes
4–5 mm
long,
0.5– 0.9 mm
wide, pale brown, with 4–5 longitudinal brown ribs, densely papillose; disc achenes
4.5–5.5 mm
long,
0.5–1 mm
wide, with four longitudinal ribs, compactly papillose. Papillae of the achenes ranging from
0.1–0.2 mm
long. Pappus scabrous, setulose; ray floret pappus
5–10 mm
long and disc floret pappus
6–12 mm
long.