Three new taxa and two noteworthy species of Peliosanthes (Asparagaceae, Convallarioideae) from Laos and Vietnam
Author
Averyanov, Leonid V.
0000-0001-8031-2925
Komarov Botanical Institute of the Russian Academy of Sciences, Prof. Popov Str., 2, 197376 St. Petersburg, Russia & av _ leonid @ mail. ru; https: // orcid. org / 0000 - 0001 - 8031 - 2925
av_leonid@mail.ru
Author
Nguyen, Van Canh
0000-0001-9578-0342
Institute of Applied Technology, Thu Dau Mot University, No. 6, Tran Van On Street, Phu Hoa Ward, Thu Dau Mot City, Binh Duong Province, Vietnam & nguyenvancanh @ tdmu. edu. vn; https: // orcid. org / 0000 - 0001 - 9578 - 0342
nguyenvancanh@tdmu.edu.vn
Author
Tanaka, Noriyuki
0000-0003-4437-2909
Hachioji-shi, Tokyo, 192 - 0352, Japan & sylvaasiaticae @ gmail. com; https: // orcid. org / 0000 - 0003 - 4437 - 2909
sylvaasiaticae@gmail.com
Author
Nguyen, Khang Sinh
0000-0001-5171-4140
Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology, 18, Hoang Quoc Viet Road, Cau Giay, Hanoi, Vietnam; Graduate University of Science and Technology, Vietnam Academy of Science and Technology. Vietnam & nskhang @ gmail. com; https: // orcid. org / 0000 - 0001 - 5171 - 4140
nskhang@gmail.com
Author
Maisak, Tatiana V.
0000-0001-5919-6755
Komarov Botanical Institute of the Russian Academy of Sciences, Prof. Popov Str., 2, 197376 St. Petersburg, Russia & tmaisak @ mail. ru; https: // orcid. org / 0000 - 0001 - 5919 - 6755
tmaisak@mail.ru
text
Phytotaxa
2023
2023-08-24
609
3
209
221
http://dx.doi.org/10.11646/phytotaxa.609.3.4
journal article
10.11646/phytotaxa.609.3.4
1179-3163
8281388
Peliosanthes nivea
Averyanov & Tanaka (2012: 157)
var.
acutiloba
N.Tanaka & Aver.
,
var. nov.
(Fig.
5 in
Averyanov
et al
. 2017
; LE: LE
01122836
https://en.herbariumle.ru/?t=occ&id=99443)
Diagnosis:
—Similar to
P. nivea
var.
nivea
, but distinguishable mainly by the somewhat basipetal (vs. acropetal) blooming, often shorter (2–4.5 vs.
3–8 mm
) floral bracts, longer pedicels (1.4–2.4 vs.
1–1.5 mm
), narrower (1.8–2.1 vs.
5–5.5 mm
wide) triangular ovate (vs. broadly ovate or broadly triangular ovate) perianth segments slightly imbricate only basally (vs. largely imbricate in the lower half), more slender conoid pistil without distinct intercarpellary wings (vs. with prominent intercarpellary wings in the distal half of pistil).
FIGURE 3.
Peliosanthes micrantha
.
A.
Habit of flowering plant, viewed from above.
B.
Basal portion of flowering plant.
C.
Leaf margins, adaxial (left) and abaxial side (right).
D.
Flowering plant.
E.
Inflorescences.
F.
Close up of inflorescence.
G.
Portion of inflorescence with some open flowers.
H.
Rachis with floral bracts, front flowers removed.
I.
Detached cataphylls, leaves, inflorescences at various stages, and seed-bearing withered flower.
J & K.
Closed or slightly open flowers.
L.
Flowers with pedicel, rear view.
M.
Two outer (above) and two inner (below) perianth segments (abaxial sides).
N.
Outer perianth segment, abaxial surface.
O.
Coronas, views from above and side.
P.
Mature flowers with dehisced anthers, longitudinally sectioned.
Q.
Basal portion of flower cross-sectioned except pistil (left), and corona and ovary cross-sectioned (right).
R.
Coronas viewed from above and below.
S.
Young green seeds of a withered flower. Photos, photo correction, and plate design by L. Averyanov and T. Maisak, specimen
L. Averyanov AL2212
.
Type
:—
LAOS
.
Type
herbarium specimen prepared on
15 April 2017
by
L
.
Averyanov
from flowering cultivated plants grown from seeds collected in
Khammouane Province
,
Thakhek District
, near
Thamnangene Cave
, around point
17°26.634N
105°56.872E
, on vertical limestone cliff, at an elevation of
157 m
a.s.l.
on
3 November 2013
,
E
. Konstantinov
K 249
.
Holotype
LE01049913
(https:// en.herbariumle.ru/?t=occ&id=2672). Photos of the cultivated plants—
LE01122836
(https://en.herbariumle.ru/?t=occ&id=99443).
Etymology
:—The varietal epithet refers to the acute perianth segments.
Description
(
the description below is based on 3-year-old plants grown from seed, hence the sizes of various portions, especially vegetative ones such as leaves, are likely to be smaller than those in adult plants in the wild
):—
Herb
lithophytic, rhizomatous, acaulescent, evergreen perennial.
Rhizome
plagiotropic, horizontal or ascending, simple to few branching, 0.8–1.2(1.6) cm long, (2.5)3–4(4.5) mm in diameter, covered with few remnants of papyraceous dull yellowish bracts.
Roots
wiry, rigid, somewhat fleshy, dirty gray.
Stem
ascending or erect, (0.8)1–1.2(1.4) cm high, covered with few linear or lanceolate papyraceous whitish bracts to
3 cm
long, (1.2)2(2.5) mm wide (when flattened).
Leaves
(6)8–12(14) cm long; petiole rigid, stout, usually curved, (2.5)3–3.5(4) cm long; leaf blade elliptic, (4.5)5–8(9) cm long, (1.8)2–3(3.4) cm wide, leathery, glabrous, somewhat rugose, adaxially grass green, glossy, abaxially light green, acute or shortly acuminate, with (5)6–9(11) main longitudinal veins; secondary transverse veinlets distinct, numerous, closely spaced, nearly parallel to each other and perpendicular to longitudinal veins.
Flowering stem
(peduncle and inflorescence rachis) (3)3.5–4.5(5) cm long, pale green, shorter than leaves; peduncle erect, stout and straight, (1)1.2–1.6(1.8) cm long, (1)1.2(1.4) mm in diameter, ebracteate or at middle with 1–2 lanceolate sterile bracts
3–4 mm
long, at the base with few small, light brownish, papyraceous bracts; rachis (1.6)1.8–3.5(4) cm long.
Floral bracts
2 (outer bract and inner bracteole), smaller above, light green to white, scarious, lanceolate or (narrowly) triangular lanceolate, acute; bract descending, (2)2.5–4(4.5) mm long, (0.7)0.8–1.2(1.3) mm wide; bracteole borne crosswise to bract and perpendicular to rachis, twice smaller.
Flowers
(4)5–12(14) flowers per rachis, somewhat basipetally blooming, drooping, solitary in bract axils, campanulate, not widely opening, (3.5)4–4.5(5) mm high, (6)6.5–7.5(8) mm (when flattened
11–12 mm
) wide in diameter.
Pedicel
cylindric, down-curved, light greenish, (1.4)1.6–2.2(2.4) mm long.
Perianth
distally 6-cleft, fleshy; tube broadly obconic, (2.8)3–3.2(3.4) mm in diameter, (0.9)1(1.1) mm high; segments
6 in
2 whorls of 3, subsimilar in shape and size, abaxial side white to pale green with purplish margins, adaxial side dark dull violet, narrowly triangular ovate, acute to subacute with obtuse tip, (3)3.2–3.8(4) mm long, (1.8)1.9–2(2.1) mm wide.
Corona
somewhat depressed (conoid) hemispheric, dark purple-violet,
0.5–0.7 mm
high, obscurely hexagonal at base, (4.2)4.4–5(5.2) mm in diameter, apical margin 6-subdentate, apical opening obscurely hexagonal to almost rounded, (1.3)1.4–1.5(1.6) mm in diameter.
Anthers
6, sessile, introrse, (broadly) ellipsoid, about
0.4 mm
long and wide, pale dull yellowish green.
Pistil
half-inferior, distal exposed portion narrowly conoid,
1.5–1.6 mm
high,
0.9–1 mm
across at base, with 3 longitudinal ridges decurrent from stigmatic lobes, without distinct intercarpellary wings at least in distal half, dark purple-violet; ovary internally incompletely 3-septate, each locule adaxially open, containing 2–3(4) ovules on central basal placentae; stigma sessile, 3-dissected, lobes elliptic, ca.
0.5–0.6 mm
long.
Seed
broadly ellipsoid to almost globular,
11–13 mm
long and wide, dark blue, glossy.
Ecology and phenology
:—Lithophytic herb on shady vertical rocky cliffs in primary or secondary lowland evergreen broad-leaved forests on limestone at the elevation of
100–200 m
a.s.l. Flowers in April.
Conservation status
:—Only a few mature individuals were found in the
type
locality. The natural environment, including the habitat, had been largely altered by the local development for promoting tourism. For lack of sufficient data on the occurrence, the conservation status of this new variety is estimated as “Data Deficient” (DD), according to the criteria proposed by
IUCN (2022)
.
Distribution
:—
Laos
,
Khammouane Province
(Thakhek District, Thamnangene Cave). Known only from the
type
locality.
Notes:
—The
type
specimen of
Peliosanthes nivea
var.
acutiloba
is the same as the material used previously for recording
P. nivea
in
Laos
(
Averyanov
et al
. 2017
).
Peliosanthes nivea
var.
acutiloba
is similar to
P. nivea
var.
nivea
and also to
P. virescens
(described in this paper),
P. argenteostriata
Averyanov & Tanaka (2012: 153)
and
P. convallarioides
Aver., N.Tanaka & K.S.Nguyen
in
Averyanov
et al
. (2021)
, as discussed below.
In contrast to acropetal blooming in
P. nivea
var.
nivea
and the three related species, the new
variety blooms
somewhat basipetally. The basipetal blooming is also known in
P. ashihoana
D.K.Roy, N.Odyuo & N.Tanaka
(
Roy
et al
. 2020: 493
) from east
India
.