The genus Begonia (Begoniaceae) in Peru
Author
Moonlight, Peter. W.
Royal Botanic Garden Edinburgh, 20 A Inverleith Row, Edinburgh, EH 3 5 LR, Scotland, UK. & Botany Department, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland.
moonligp@tcd.ie
Author
Jara-Muñoz, Orlando A.
Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Bogotá D. C., Colombia.
oajaram@unal.edu.co
Author
Purvis, David A.
Royal Botanic Garden Edinburgh, 20 A Inverleith Row, Edinburgh, EH 3 5 LR, Scotland, UK.
dpurvis@rbge.org.uk
Author
Delves, Jay
Royal Botanic Garden Edinburgh, 20 A Inverleith Row, Edinburgh, EH 3 5 LR, Scotland, UK.
j.delves@westernsydney.edu.au
Author
Allen, Josh P.
Royal Botanic Garden Edinburgh, 20 A Inverleith Row, Edinburgh, EH 3 5 LR, Scotland, UK.
myrmeciaman@gmail.com
Author
Reynel, Carlos
Facultad de Ciencias Forestales, Universidad Nacional Agraria-La Molina, Lima 12, Peru.
reynel@lamolina.edu.pe
text
European Journal of Taxonomy
2023
2023-07-18
881
1
334
http://dx.doi.org/10.5852/ejt.2023.881.2175
journal article
287311
https://doi.org/10.5852/ejt.2023.881.2175
225ee515-e526-4cc0-b86b-85e8f2e4c83a
2118-9773
8178280
73.
Begonia occultata
J.P.Allen & Moonlight
sp. nov.
urn:lsid:ipni.org:names:77323298-1
Figs 90A
,
92
Diagnosis
Most similar to
B. cremnophila
Tebbitt
but differing in its glabrous leaves (vs sparsely pilose to sparsely pubescent on the upper surface, pilose on the veins on the lower surface); its lanceolate bracts with an entire, aciliate margin (vs obovate with a denticulate, ciliate margin); and tepals that do not persist in fruit.
Etymology
The epithet derives from the Latin ‘
occultatus
’, meaning ‘hidden’ or ‘concealed’. It refers to the species’ patterned leaves, which are camouflaged against the forest floor.
Type
PERU
–
Puno Region
:
Prov. Sandia
•
Dist. San Pedro de Putina Punco
,
ca
7.5 km
S of San Pedro de Putina on the road 34H to San Juan del Oro
;
14°09′17″ S
,
69°04′08″ W
;
1068 m
a.s.l.
;
6 Feb. 2021
;
J.P. Allen
2
;
holotype
:
HUT
[61143].
Description
Acaulescent, rhizomatous herb, to
32 cm
high.
Rhizome
discoid to ellipsoid, 2.5–7 ×
3–5 cm
, with 1 growing point.
Stipules
persistent, triangular, 3–4.5 ×
5.5–12 mm
, apex acute, apiculate, translucent, green flushed red, glabrous, margin entire, aciliate.
Leaves
2–4, alternate, basifixed; petiole
1.5–11 cm
long, deep red, glabrous; blade asymmetric, transversely ovate, to 21.5 ×
15.5 cm
, succulent, apex acute, base cordate, basal lobes overlapping, sinus to
35 mm
deep, margin repend, ciliate, upper surface dark green, the veins flushed pale green and flecked silver, often iridescent blue, glabrous, lower surface deep red, the veins flushed pale green, sparsely scabrous, veins palmate with one major vein, 6–8 veined from the base, with 2–4 secondary veins on the larger side, 1–3 secondary veins on the smaller side.
Inflorescences
1–3, bisexual, axillary, erect, cymose, with 2 branches, bearing up to 6 staminate flowers and 3 pistillate flowers, protandrous; peduncle to
26.5 cm
long, red, glabrous, bracts deciduous, triangular, 2–4.5 ×
3.5–10 mm
, translucent, pale green, glabrous, apex acute, margin entire, aciliate.
Staminate flowers
: pedicels to
13.5 mm
long, glabrous; tepals 4, spreading, outer 2 broadly ovate, 4.5– 9.5 ×
5–7.5 mm
, apex obtuse, base rounded, white, glabrous, margin entire, aciliate, inner 2 oblanceolate, 4.5–7 ×
2–4.5 mm
, apex rounded, base cuneate, white, glabrous, margin entire to serrulate, aciliate; stamens ca 25, spreading, pale green, filaments ca
2.5 mm
long, fused at the base, anthers obovoid, 1.2 ×
0.8 mm
, dehiscing via lateral slits, connectives not extended, symmetrically basifixed.
Pistillate flowers
: pedicels to
5.5 mm
long; bracteoles lacking; tepals 5, subequal, deciduous in fruit, projecting, elliptic to ovate, 4–7.5 ×
1.5–3.5 mm
, apex obtuse, white, flushed pink outside, glabrous, margin entire, aciliate; ovary body broadly ovate, ca 3.5 ×
2.5 mm
, green flushed red, glabrous, unequally 3-winged, the largest wing triangular, ca 6 ×
5 mm
, smallest semi-circular, rib-like ca
1.5 mm
wide; 3-locular, placentae branches divided, bearing ovules on both surfaces; styles 3, yellow, free, ca
2.5 mm
long, once-divided, stigmatic papillae in a twice spirally-twisted band.
Fruiting pedicel
to
20 mm
long.
Fruit body
ovoid, to 9.5 ×
6.5 mm
, drying brown, wings same shape as in ovary, the largest expanding to
13.5–20 mm
, the smallest expanding to
4 mm
wide.
Fig. 92.
Begonia occultata
J.P.Allen & Moonlight
sp. nov.
A
. Habit.
B
. Leaf, adaxial surface.
C
. Leaf, abaxial surface.
D
. Fruit, side view.
E
. Staminate flower, front view.
F
. Staminate flower, side view.
G
. Pistillate flower, side view. All photographs taken by J.P. Allen from
J.P. Allen 2
in Sandia Province, Puno Region.
Proposed conservation assessment
Known from a single population immediately adjacent to the main road through Sandia Province. During fieldwork in
November 2020
and
February 2021
, ca 50 individuals were observed and a second population with ca 15 individuals was located ca
8 km
southwest along the 34H at
14°12′57″ S
69°06′40″ W
. Both populations are within
50 m
of a main road and
300 m
of built-up areas. Given the species’ small range and population size, and its proximity to a major road and human habitation, we assess
B. occultata
sp. nov.
as Critically Endangered (CR B1ab(iii); C1+2a(i)).
Notes
The new species does not fit into any of the two large sections of tuberous Andean
Begonia
. It differs from species in
B.
sect.
Eupetalum
in its bifid rather than multifid styles, and from
B.
sect.
Australes
in lacking a stem. It is most similar to
B. cremnophila
, which is found ca
750 km
to the southwest in
Chuquisaca
and
Santa Cruz
Departments,
Bolivia
.
Begonia cremnophila
was included in recent molecular phylogeny (
Moonlight
et al.
2018
) and was placed among a diverse group of Andean species that remain unplaced to section. We therefore treat
B. occultata
sp. nov.
as unplaced to section.
Identification notes
Begonia occultata
sp. nov.
is difficult to distinguish from the southern Bolivian endemic species
B. cremnophila
(see Diagnosis). Within
Peru
, however, it is recognised as the only acaulescent and tuberous
Begonia
with no indumentum and a distinct apex to the leaf.
Distribution and ecology
Endemic to
Peru
and
Puno Region
(
Fig. 90A
). Found within lower montane forest at an elevation of
1050–1200 m
a.s.l.
Begonia occultata
sp. nov.
is tuberous and has been observed emerging from dormancy at the start of the wet season in September and flowering and fruiting in February. The tubers were collected on a moist bank in relatively seasonal montane forest where the patterned leaves are very inconspicuous, perhaps acting like camouflage.