New species in Diplusodon (Lythraceae) from Brazil
Author
Cavalcanti, Taciana B.
text
Phytotaxa
2015
2015-09-11
226
2
144
156
http://dx.doi.org/10.11646/phytotaxa.226.2.4
journal article
10.11646/phytotaxa.226.2.4
1179-3163
13636314
3.
Diplusodon venosus T.B. Cavalc.
,
sp. nov.
Type
:—
BRAZIL
.
Goiás
:
Cavalcante
, entroncamento
Minaçú-Kalunga
(Engenho Dois), km 5,
13º36’06”S
,
47º28’29”W
,
31 August 2004
(fl., fr.),
Cavalcanti et al. 3534
(
holotype
CEN
!;
isotype
SPF
!).
Figure 4
.
Species characterized by the upper branches straw-colored, leaf blades 50–70 ×
6–26 mm
, very distinct from bracts (
1–4 mm
wide), long bracteose inflorescence and flowers with 18–24 stamens.
Subshrubs
0.35–0.7 m
tall, glabrescent, foliage lax. Branches slightly quadrangular and flattened, with an inconspicuous wing, the upper branches straw-colored, with minute and very inconspicuous trichomes to glabrous, internodes
3–4.5 cm
long. Leaves decussate, rarely verticillate, not imbricate, erect, coriaceous, subsessile, not discolorous, not glaucous, not dark brown when dry, eucamptodromous to acrodromous; petiole
0.5–1 mm
long; blades 50.5–70 ×
6–26 mm
, narrow-elliptic or narrow-lanceolate to wide-elliptic, base obtuse to acute, apex acute, slightly acuminate, margin plane, irregular, with minute and inconspicuous cilia, blades glabrescent to glabrous, trichomes when present slightly bulbose at the base, sparse, common on the abaxial surface; veins 2 or 3 along the midvein, very prominent; domatia present, inconspicuous. Synflorescence bracteose, triplobotryum to pleiobotryum
type
, lax; accessory branches absent, principal florescence of the botryum
type
, usually truncate, paraclades
5–25 cm
long; bracts 15–30 ×
1–4 mm
, glabrous, linear to narrow-elliptic; flowers short-pedicelate, hypopodium
0.5–1 mm
long, epipodium to
0.5 mm
long; prophylls 4–4.2 ×
1.5–1.7 mm
, surpassing the middle of the floral tube, almost reaching the apex of the floral tube, narrow-elliptic to obovate, keeled, base retuse to acute, apex acute, margin plane; floral tube
4.5–5 mm
long, funnel-shaped, glabrous; sepals
2–2.2 mm
long, triangular, not deflexed, glabrous; epicalyx segments ca.
2 mm
long, slightly dorso-ventrally compressed, spreading, glabrous, shorter than the sepals; corolla
3.5–4 cm
in diam., lilac to rose-magenta, petals 13–19 ×
7–10 mm
, obovate, apex obtuse; stamens 18–24, free portion of the filaments
6–6.5 mm
long, slightly exserted; ovary 2–2.2 ×
2.2–3 mm
, obtrapezoidal, glabrous, style
7–10 mm
long, ovules 22–42. Capsules 4.5–5 ×
4–4.5 mm
, globose, glabrous; seeds ca. 31, 1.5–2.2 ×
1.5–2.8 mm
.
Distribution and ecology:—
Diplusodon venosus
is known only from the municipality of Cavalcante in the vicinity of the traditional community Kalunga. It inhabits cerrado and fields on sandy soil with sandstones at
919–1,030 m
. Flowers from March to July; fruits April to September.
Etimology:—Specific epithet related to conspicuously veined leaves.
Paratypes
:—
BRAZIL
.
Goiás
:
Cavalcante
, aldeia
Kalunga
,
6 March 2003
(fl.),
Pastore
&
Suganuma
444
(
CEN
!)
;
Cavalcante
, estrada para
Prata
(
Kalungas
),
13º22’24”S
,
47º41’9.1”W
,
Cavalcante
, comunidade
Kalunga
, caminho para a cachoeira
Capivara
,
20 April 2003
, (fl.),
Pastore
et al. 471
(
CEN
!)
;
Cavalcante
, comunidade
Kalunga
,
20 April 2003
, (fl.),
Pastore
et al. 473
(
CEN
!)
;
Cavalcante
, estrada para
Prata
(
Kalungas
),
13º22’24”S
,
47º41’9.1”W
,
14 April 2004
(fl.),
Fonseca
et al. 5095
(
CEN
!,
HRB
!,
IBGE
!)
.
Comments:—
Diplusodon venosus
is another unusual species of the genus from the mountains of
Goiás
. The upper branches are straw-colored, the bracteose inflorescence is long, broad and conspicuous, with distinct linear to narrow-elliptic bracts different from the vegetative leaves, especially in size. The leaves are variable in width, ranging in shape from narrow-elliptic, narrow-lanceolate to wide-elliptic, but always with strongly prominent veins, also present on the bracts. Because of the bracteose inflorescence, the species resembles
D. astictus
Lourteig (1963: 6)
and
D. ramosissimus
Pohl (1827: 151)
, which also occur in the region. However,
D. astictus
has upper branches wine-colored to chestnut, and larger flowers with 12 stamens. In
D. ramosissimus
the leaves have conspicuous domatia and the flowers have very short prophylls, not reaching the middle of the floral tube.