The restablishment of Dyckia oligantha and D. nana (Bromeliaceae, Pitcairnioideae), belonging to the D. macedoi complex
Author
Guarçoni, Elidio Armando Exposto
Author
Azevedo, Aristéia Alves De
Author
Costa, Andrea Ferreira Da
text
Phytotaxa
2017
2017-05-05
306
1
49
65
http://dx.doi.org/10.11646/phytotaxa.306.1.4
journal article
10.11646/phytotaxa.306.1.4
1179-3163
2.
Dyckia nana
Leme & Ribeiro (
Leme
et al.
2010: 36
)
,
Figs. 4 E–H
,
5 D–E
Type
:—
BRAZIL
,
Minas Gerais
: Diamantina, est. Diamantina para Conselheiro Mata, ca.
10 km
de Conselheiro Mata,
18º18.50’S
,
43º53.43’W
,
1288 m
elev.,
25 June 2008
, fl.,
E. Leme, C.C. Paula, T. Coser, R. Moura & O.B.C. Ribeiro 7484
(
holotype
RB!,
isotype
HB!).
Plant
terrestrial, flowering
19–41.5 cm
high.
Leaves
8–17 in
number, rigid, succulent, slightly recurved, forming an asymmetric rosette, caused by the second leaves, 4.4–7 ×
7.2–8.7 cm
;
sheaths
suborbicular, ca. 2 ×
4 cm
, white with the upper abaxial half brown, white lepidote on the upper third of both surfaces, inconspicuously spinose distally;
blades
narrowly triangular, 3–6.7 ×
0.6–1.4 cm
, distinctly canaliculate, green abaxially, vinaceous adaxially, white lepidote on both surfaces, slightly or not obscuring the leaf color, apex acuminate, pungent, margins spinose except for the apical third, spines the basal ones antrorse to patent in the median ones, brown, 0.6–1.4 ×
0.1 mm
,
4–10 mm
apart.
Inflorescence
simple, erect, (21.4–)
28–39.6 cm
long;
rachis
orange,
1.1–1.4 mm
in diameter, white tomentose;
fertile part of the inflorescence
4.7–9.5 cm
;
peduncle
erect, terete, (15–)
23.3–31.7 cm
long,
1–1.8 mm
in diameter, green, glabrous, internodes (17–)23–35.1(–40.8) mm long;
peduncle bracts
shorter than the internodes, lower ones 1.3–3.4 ×
0.2–0.4 cm
, upper ones 4.6–8 ×
1.2–3.4 mm
, ovate to oblong, acuminate, ending in a spine, stramineous, carinate, the lower ones white lanate abaxially, the upper ones glabrous, margins entire.
Floral bracts
equaling or slightly exceeding the pedicels, 3.4–8 ×
2.6–5.3 mm
, orange, broadly ovate, patent, convex, ecarinate, acuminate, ending in a spine, white lanate abaxially, margins with fimbriate trichomes along the basal half.
Flowers
5–13 in
number, antrorse,
1.2–1.5 cm
long;
pedicels
evident, orange, (3.2–)
4.2–6.8 mm
long, sparsely white lanate;
sepals
symmetric, reaching the midpoint of the petals, orange, ovate to ellipitc, 4.7–8.3 ×
3.1–5.1 mm
, obtuse or with an inconspicuous apiculus, sparsely white lanate abaxially, margins with fimbriate trichomes;
petals
symmetric, orange, rhombic, 7.5–7.7 ×
4.2–5.2 cm
, obtuse, margins entire, glabrous; corolla tubular.
Stamens
included;
filaments
pale yellow, linear,
4.8–5.3 mm
long, connate at the base for
1.4–1.5 mm
to form a common tube with the petals, free above it;
anthers
linear,
1.5–1.7 mm
long, acute, recurved at the apex, yellow, dorsifixed near the base.
Ovary
superior part oblong, yellow to pale orange,
3.8 mm
long;
style
yellow,
1.3 mm
long;
stigma
,
0.5–0.9 mm
long, yellow.
Capsules
ovoid, dark brown, 8.6 × 6,
3 mm
, suberect to erect.
Additional specimen examined:—
BRAZIL
,
Minas Gerais
:
Diamantina, Km
165, estr. para
Conselheiro Mata
, MG-220,
25 February 1987
,
Zappi
et al
. (
SPF 46903
)
;
15 March 1999
,
Rapini
746 &
Kawasaki
(
SPF
)
;
estr.
Diamantina-Conselheiro Mata
, 38
Km
do trevo de saída de
Diamantina
,
31 January 2000
,
Forzza
&
Mello-Silva
1510
(
BHCB
; SP;
SPF
)
;
estr. para
Conselheiro Mata
, lado esquerdo,
1241 m
elev.,
18º18’24”S
–
43º53’59”W
,
25 May 2011
,
Guarçoni
1671 &
Paixão
(
VIC
).
Gouveia
, estr. do lado esquerdo da BR-259 para
Gouveia
,
5 August 2010
,
Guarçoni
1478 et al.
(
MACO
).
Presidente Kubitschek
, estr.
Datas
to
Serro, KM
438,
18º33’00”S
–
33º33’00”W
,
11 March 1998
,
Forzza
et al. 679
(
RB
)
.
Distribution and habitat:
—
Dyckia nana
is endemic to the
Diamantina Plateau
, occurring between 1000 and
1240 m
elevation. The species habit can be terrestrial or saxicolous, and individuals usually occur on soils with quartz rubbles.
Phenology
:—Flowering from January to May.
Conservation Status
:—The species is critically endangered (CR), as it is known from only three localities, with a total estimated population of less than 250 individuals. These areas are severely affected by annual fires. The species does not occur in Conservation Units.
Comments
:—
Dyckia nana
is mainly characterized by small and asymmetric rosettes with few slightly recurved leaves. Another character that can aid recognition is the suberect flowers at anthesis.
The species can be distinguished from
D. oligantha
by having fewer leaves (9–17
vs.
21–41), sheath white-lepidote on the upper third (
vs.
glabrous), peduncle bracts glabrous (
vs.
white-lepidote); flowers suberect (
vs.
slightly reflexed), pedicels
4.2–6.8 mm
(
vs.
2–4 mm
), sepals obtuse (
vs.
acute), narrower petals (
4.2–5.2 mm
vs.
5.9–9.2 mm
), and longer style (
1.3 mm
vs
.
0.8 mm
).
Dyckia nana
had been synonymized with
D. macedoi
by Forzza
et al.
cont. upd. without additional comment.