THE VIOLETS OF THE BRAZILIAN SAVANNA: A REVISION OF THE POMBALIA LANATA COMPLEX (VIOLACEAE), WITH DESCRIPTIONS OF TWO NEW SPECIES
Author
Paula-Souza, J.
Author
Lima, A. G.
Author
Souza, V. C.
text
Edinburgh Journal of Botany
2021
2021-04-07
78
357
1
32
http://dx.doi.org/10.24823/ejb.2021.357
journal article
285207
10.24823/EJB.2021.357
79160911-6a72-466a-b594-3a50c8a4341c
1747-0036
10513850
5.
Pombalia strigoides
(Taub.) Paula-Souza, Phytotaxa
183(1): 11, f. 1F, 3G, 5B (2014).
–
Hybanthus strigoides
Taub., Bot. Jahrb. Syst.
21: 445 (1896)
.
Type:
Brazil
. “
Goyaz
. Auf
Chapadao der Morro do Salto
”,
ix 1892
,
E.Ule
2752/58 (
lectotype
HBG
! [
HBG506559
], designated by Paula-Souza in
Paula-Souza & Ballard, 2014
;
isolectotype
P
!,
R
!)
.
Figures 1C
,
9A–D
,
10A–E
.
Suffrutescent herb,
8–20 cm
high, branched from a well-developed, bud-bearing underground root-like system, erect;
internodes
2.5–16.5 mm
.
Stipule
c.1
×
c.
0.6 mm
, margin entire;
leaves
alternate, sessile and usually adpressed to the stems;
blade
4–7.9
×
1.5–3 mm
, narrowly elliptic to elliptic, oblong, less frequently linear, apex acute, frequently obtuse or slightly acuminate, margin entire, base acute to obtuse, strigose, sometimes the hairs condensed at midrib, hairs simple, closed-pressed.
Flowers
purple, blue or lilac with a yellow or white spot at the base of the anterior petal, rarely white, solitary, axillary;
pedicel
6.8–16.5 mm
, strigose;
bracteoles
c.1
×
c.
0.4 mm
;
sepals
subequal, 3.6–6.7
×
1.1–2.4 mm
, lanceolate, frequently subfalcate, margin entire, base truncate or rounded, strigose;
posterior petals
4.7–6.5
×
1.3–2.7 mm
, narrowly oblong, oblong-lanceolate or less frequently ovate;
lateral petals
9.5–14
×
2.7–7 mm
, oblong, frequently constricted at the central portion, or clawed, falcate, sparsely villous;
anterior petal
14.5–17.5
×
16–22 mm
, including a claw
4.7–6.8 mm
long, transversely oblong, obtriangular, apex slightly to deeply emarginate, smooth, villous;
filaments
0.8–1.2 mm
, connective appendages hyaline,
1–1.2 mm
long, nectar glands noduliform, rarely much reduced, inserted on the filaments or near the base of the anthers, villous;
style
3 mm
, glabrous, sigmoid, ovary
1.1–1.8 mm
, villous to strigose.
Capsule
6
×
c.
6 mm
, ovoid;
seeds
c.3
×
c.
2.5 mm
.
Figure 9
. A–D,
Pombalia strigoides
: A, habit; B, habitat; C, configuration of the androecium around the gynoecium (
an
, anther;
ca
, connective appendage;
gl
, nectar gland;
pp
, posterior petal;
st
, style); D, detail of flowering branch; E–G,
Pombalia velutina
: E, root system (bud indicated by arrow); F, flowering branch of congested inflorescence; G, detail of broad, fimbriate sepals (arrow). Photographs by Juliana de Paula-Souza.
Figure 10
. A–E,
Pombalia strigoides
: A, habit; B, gynoecium; C, variation of size and shape of the corolla; D, calyx; E
1
, posterior stamen; E
2
–E
4
, variation of size, indument and shape of connective appendage of anterior stamens. F,
Pombalia cristalina
Paula-Souza
,
sp. nov.
: anterior stamen. Drawn from
Gifford & Fonseca
243 (A),
Irwin
et al. 9355 (B and E
3
),
Rizzo
8407 (C
1
, D, E
1
and E
2
),
Heringer
2503 (C
2
and E
4
) and
Proença & Oliveira
1562 (F) by Rogério Lupo.
Etymology
. The epithet refers to the plant’s resemblance to species of the parasitic genus
Striga
Lour.
(witchweed) in the
Orobanchaceae
.
Distribution and habitat
.
Pombalia strigoides
is restricted to campos rupestres, grasslands and savannas of Chapada dos Veadeiros region, northeastern
Goiás state
,
Brazil
(see
Figure 3
).
Phenology
. The species has been collected with flowers and fruits from September to November, with a single flowering record in August.
Conservation status
. Although there are records of
Pombalia strigoides
populations within the limits of conservation units, the species has nonetheless a restricted distribution in a region marked by the conversion of natural ecosystems into agricultural areas. According to
IUCN (2012)
criteria B1b(i,iii) +2b(ii,iii), this species is considered Critically Endangered (CR) based on its limited distribution (AOO,
8 km
2
; EOO, not measurable) and the continuing decline in the quality of its habitats.
Selected specimens examined
.
BRAZIL
.
Goiás
:
Alto Paraíso de Goiás
, Rod. GO-118 em direção a
Cavalcante
, c.
20 km
N
(em linha reta)
de Alto Paraíso
, 13°57′40.2′′, 47°28′26.1′′,
1516 m
a.s.l.
,
23 x 2012
,
Paula-Souza
et al. 11341/715 (
ESA
,
HUEFS
,
MBM
,
RB
)
;
Chapada dos Veadeiros
,
27 km
de Alto Paraíso
/
Colinas
, campo limpo acima
da Mata Funda
,
24 xi 1994
,
M
.
A
.
Silva
et al. 2398 (
IBGE
)
.
Typical forms of
Pombalia strigoides
are easily distinguished by their very reduced leaves 4–7.9
×
1.5–3 mm
, which are usually adpressed to the stems, and by the strigose indument of vegetative and floral parts.