Myrcia urquiolae (Myrtaceae), a new species from eastern Cuba
Author
Ramos, Zenia Acosta
Centro de Investigaciones y Servicios Ambientales ECOVIDA, Agencia de Medio Ambiente, CITMA, Carretera a Luis Lazo km 2 ½, Pinar del Río, Cuba. C. P. 20100.
Author
Hechavarría, José Luis Gómez
Jardín Botánico de Holguín, Centro de Investigaciones y Servicios Ambientales de Holguín (CISAT), Agencia de Medio Ambiente, CITMA, Carretera al Valle de Mayabe km 5 ½, Holguín, Cuba.
text
Phytotaxa
2022
2022-06-02
549
1
111
111
journal article
62928
10.11646/phytotaxa.549.1.10
00f36cc1-9fb2-47a4-9b8f-03f27e96555d
1179-3163
6605248
Myrcia urquiolae
Z. Acosta
,
sp
.
nov
.
(
Figures 1
,
2
and
3
).
Type
:—
Cuba
, Prov.
Holguín
, municipio
Mayarí
,
Sierra de Nipe
, charrascales de La Caridad cerca del
río Naranjo
,
13 June 2018
,
Z. Acosta
&
J.L. Gómez
s.n.
(
holotype
HAJB
1255!; isotypes:
B
!,
FTG
!,
HAC
!,
HAJB
1254!,
HAJU
!,
HJBHO
!, PAL-Gr 129938!)
.
Diagnosis
:—
Myrcia urquiolae
differs by all Cuban congeneric species by its strongly revolute linear leaves.
Description
:—
Small tree
up to
7 m
high, branchy; old branches cylindrical, glabrous, olive-green with longitudinal and scaly striations due to the loss of the suber; the young branches quadrangular, bright green, with abundant simple hairs and glands visible as black dots.
Leaves
opposite; petioles
1–2 mm
long, ca.
1 mm
wide, cylindrical, glabrous; laminas linear, 2.5–4 ×
0.15–0.3 cm
, bright green and glabrous on the upper surface, brownish green on the underside and brown tomentose on the midvein, bright brown on the upper surface and light brown on the underside when dry, coriaceous, glandular dotted, apex acute to obtuse, base acute to rounded, margin strongly revolute, entire, middle vein sunken on the upper surface and prominent on the underside, secondary veins not visible on both surfaces.
Inflorescences
in axillary panicles, with up to 10 flowers, peduncles
2–5 cm
long, white-tomentose.
Flowers
with pedicels
2–3 mm
long; bracts filiform, albo-tomentose, 1.5–2 ×
0.5–0.8 mm
, persistent after anthesis; hypanthium albotomentose, conical.
Calyx
4–merous, opening irregularly, white-tomentose, with abundant visible glands, sepals 1.5–2 ×
1–1.5 mm
, apex acute.
Petals
4, yellowish–white, deltoid, glandular-dotted, 2–3.5 ×
1.5 mm
.
Stamens
numerous, filaments white, 5–6 ×
0.2 mm
; staminal ring thickened,
0.4–0.5 mm
thick; anthers light brown, rounded to oblong, 0.5–1 ×
0.5 mm
, two thecae.
Ovary
white-tomentose, glandular, bilocular with 2 ovules per locule; style 10–12 ×
0.4–0.5 mm
, stigma truncate, 0.6–07 diameter.
Fruits and seeds
unknown.
FIGURE 3.
Geographical location of the
Myrcia urquiolae
population in Holguín (eastern Cuba), La Mensura-Piloto National Park, near the Naranjo river, in the charrascales of La Caridad.
Etymology
:—The epithet is dedicated to Dr.Armando Jesús Urquiola Cruz (1949–2009), eminent Cuban botanist, founder of the Botanical Garden of Pinar de Río, who dedicated his life to the study and conservation of the flora of Pinar de Río, the
Myrtaceae
family and Cuban aquatic plants. Professor Urquiola was the first to recognize this species as new to science, in an expedition with the first author in 2007.
Distribution and habitat
:—Local endemic species of Sierra de Nipe. It is only known from the Charrascales de La Caridad, near the Naranjo river (
20.474592 N
; -
75.740322 W
), Mayarí municipality,
Holguín province
(
Figure 3
). It grows in xeromorphic sub-thorny thickets over serpentinite rocks, on ferromagnesian red-brownish fersialitic soils, between
300–450 m
elev. The shrub strata of the charrascal, where the species lives, varies between
3–4 m
in height and its cover on the ground is 70–80%. Species composition include
Mazaea shaferi
(
Standley 1918: 42
)
Delprete (1999: 221)
,
Metopium venosum
(
Grisebach 1866: 67
)
Engler (1883: 367)
,
Miconia rosmarinifolia
(
Grisebach 1866: 93
) M.
Gómez (1894: 68)
,
Psychotria rufovaginata
Grisebach (1866: 136)
,
Plumeria nipensis
Britton (1915: 505)
y
Solenandra myrtifolia
(
Grisebach 1866: 125
)
Borhidi (2002: 227)
.
Reproductive biology
:—Tiny yellowish-white flowers with numerous stamens indicate probable insect pollination. Although the fruits of the new species are unknown, dispersal by birds has been reported for other
Myrcia
species
(
Torezan-Silingardi & Alves 2004
).
Conservation status
:—
Myrcia urquiolae
is known from only one locality, which was affected by fire in
March 2019
. In the only population known to date,
25 adult
individuals have been registered in an extent of occurrence and area of occupation of
1 km
2
. Although this locality is located within La Mensura-Piloto National Park, a managed protected area of national significance, this site is vulnerable to increased fire frequency. For this reason, a future decrease in the area, extent and quality of habitat and in the number of mature individuals is projected. Therefore, according to
IUCN (2019)
criteria, the available data support the evaluation of
Myrcia urquiolae
as Critically Endangered (CR), by criteria: B1ab(ii, iii,v)+2ab(ii, iii,v); C2a(i,ii); D.
Taxonomic remarks
:—
Myrcia urquiolae
belongs to
Myrcia
sect.
Myrcia
due to its hairy floral disc and the nonprolonged hypanthium on the summit of the ovary, characters that distinguish it from the other sections of the genus. Additionally, it presents a thickened staminal ring, which comprises more than 50% of the disc (vs. less than 30% in
Myrcia
sect.
Gomidesia
(O.
Berg 1855
–1856: 5) B. S. Amorim & E. Lucas in
Lucas
et al.
2018: 9
), and anthers with thecae of equal size that open completely in two equal parts (vs. vertically displaced that retain curvature at dehiscence) (see
Lucas
et al
. 2018
). The phylogenetic position of
M. urquiolae
in
Myrcia
sect.
Myrcia
was proven by
Flickinger
et al
. (2020
, as
Myrcia
sp. 1
), where in the phylogeny of the family for the Greater Antilles it nested along with
M. apodocarpa
Urban (1923: 87)
,
M. retivenia
(C.
Wright 1869: 433
)
Urban (1923: 86)
and
M. abbottiana
(Urban 1925: 341)
Alain (1971: 138)
. Regarding the other species of the section in
Cuba
,
M. urquiolae
differs by its strongly revolute linear leaves.