Parablechnum roraimense and P. paucipinna spp. nov. (Blechnaceae: Polypodiopsida), lectotypification of P. stuebelii, and citation corrections in the family
Author
Dittrich, Vinícius Antonio De Oliveira
Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer, s. n.
Author
Smith, Alan R.
Author
Gasper, André Luís De
Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer, s. n. & Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer, s. n.
text
Phytotaxa
2017
2017-01-20
292
1
65
73
http://dx.doi.org/10.11646/phytotaxa.292.1.6
journal article
10.11646/phytotaxa.292.1.6
1179-3163
13698007
Parablechnum paucipinna
A.R.Sm.
,
sp. nov.
(
Fig. 1
)
Type:—
VENEZUELA
. Edo.
Bolívar
: Sierra de Lema, sector La Escalera, al Este de la carretera, a unos
200 m
del salto El Danto en dirección N-S,
05°57’54”N
,
61°23’42”W
, bosque de galería muy húmedo,
1250–1300 m
,
23 Apr 2006
,
Y. Vivas, B. Holst, J. Tillet &
S
. Fawcett 1553
(
holotype
UC-2044673,
isotypes
SEL, VEN, not seen).
Plants
rupicolous;
rhizomes
compact, concealed by stipe bases and root mass, lacking stolons, caudex
ca.
2 cm
diam.; rhizome apex scales concolorous, tan to brownish, basifixed or nearly so, lanceolate to ovate-lanceolate with a caudate apex, 8–10 ×
1–2.5 mm
, margins entire or nearly so;
leaves
clustered, ca.
35 cm
long, the fertile and sterile strongly dimorphic, but similar in length;
stipes
stramineous, or darkening with age, glabrous above the basal
2–3 cm
, sulcate adaxially, with conspicuous transverse wrinkles throughout, the sterile to
20 cm
×
2–3 mm
, about the same length as the blades, the fertile to
25 cm
, twice as long as blades, the basal scales to
ca.
6 ×
2 mm
, entire, lacking marginal setae, not or only weakly pectinate at bases, similar to those of rhizome apices but lighter tan;
blades
chartaceous, the sterile ca. 20 ×
15 cm
, deltate, lowest pinnae the longest or nearly so (lacking vestigial proximal pinnae), 1-pinnate, lateral pinnae 4 or 5 pairs, ascending ca. 45 degrees from rachis, to 9 ×
1.6 cm
, stalked
1–5 mm
, bases rounded to cuneate, each pinna with a low, blackish, tuberculiform aerophore at its base, pinna apices abruptly attenuate and minutely toothed at the tips, margins otherwise entire, not revolute; sterile blade apices conform or with a single basal lobe, ca. 8 ×
1.6 cm
, fertile pinnae delicate,
ca.
4 pairs per frond, each
ca.
5 cm
×
1 mm
;
rachises
stramineous or brownish, with transverse ridges like those of stipes, sulcate adaxially, bearing sparse tan scales
ca.
0.5–3 ×
0.1–0.4 mm
along the costae abaxially, lacking hairs;
veins
simple or once-forked near their base, free, closely parallel (set
ca.
0.5 mm
apart midway between costae and pinna margin), without enlarged endings (hydathodes) adaxially, not significantly raised on either side, but darkened abaxially;
costae
abaxially with rather sparse, filiform to lanceolate tan scales, the larger ones widened and pectinate at their bases, mostly
0.5-1.5 mm
long, veins and laminar tissue lacking scales on both sides;
sori
linear, continuous, parallel to the costae, bearing filiform scales along the costae abaxially; indusia very narrow, glabrous, entire, at least at maturity; spores not seen.
Distribution and habitat:—
This species grows on rocks, with fronds clumped, in montane rain forests at ca.
1300 m
. The rhizomes are obscured by the compact, fine root mass. Known only from the
type
.
Etymology:—
Named for the few pinna pairs on relatively small fronds.
Notes:—
This may be the most delicate species yet described in
Parablechnum
—relatively thin-textured compared to other species in the genus, and virtually scaleless or with mainly tan, small, filiform, scales on costae and rachises. There are only few pinna pairs, up to
ca.
5, in both sterile and fertile fronds; the fertile pinnae are exceedingly narrow, only about
1 mm
wide, the narrowest for any known species of
Parablechnum
. Nearest affinities are uncertain.