Vines and Climbing Plants of Puerto Rico and the Virgin Islands

Vines and Climbing Plants of Puerto Rico and the Virgin Islands 29
1. DICRANOPTERIS
Terrestrial ferns; rhizomes elongate, creeping with setulose trichomes, without scales. Fronds
monomorphic, with periodic indeterminate growth, 4-5 times bifurcate; pinnae, pinnules, and secondary
pinnules opposite, the secondary venation 2-4 times bifurcate, the lower surface glaucous; petioles
brittle and glabrous. Sori rounded, without an indusium, on the secondary veins, with 6-15 sessile
sporangia. A tropical genus of about 10 species.
Key to the species of Dicranopteris
1a. Area of frond bifurcation with a pair of accessory pinnae; tertiary rachis of the fronds slightly
angular; lower surface pale green, glabrous ............................................................... 1. D. flexuosa
1b. Area of frond bifurcation without accessory pinnae or sometimes with accessory pinnae only in the
primary bifurcations; tertiary rachis of the fronds with narrow longitudinal keels; lower surface
glaucous, glabrous, or sometimes with scattered stellate hairs ................................ 2. D. pectinata
1. Dicranopteris flexuosa (Schrad.) Underw.,
Bull. Torrey Bot. Club 34: 254. 1907.
Fig. 8. A-E
BASIONYM: Mertensia flexuosa Schrad.
SYNONYM: Gleichenia flexuosa (Schrad.) Mett.
Terrestrial fern. Rhizomes creeping, with
deciduous setose trichomes. Fronds clambering
or decumbent, 1-2 m long, forming a dense thicket
difficult to penetrate; pinnae 4 times bifurcate,
with a pair of accessory pinnae of reduced size
and a tuft of rigid, reddish trichomes in the area
of bifurcation; rachis cylindrical and brittle, the
primary rachis with proleptic indeterminate
growth, the secondary or tertiary rachis of
determinate growth, the latter angular; secondary
pinnules oblong-deltoid to linear, glabrous, the
secondary venation 2-4 times bifurcate, the apex
obtuse, the margins revolute; lower surface pale
green, glabrous. Sori reddish brown, 0.2-0.4 mm
in diameter.
Phenology: Probably found in fertile condition
throughout the year.
Status: Native, very common.
Distribution: Widely distributed in moist
disturbed areas along varying elevational
gradients. Also in the Antilles, the United States
(Florida), Central America, and tropical South
America.
Public forests: Carite, El Yunque, Maricao,
Río Abajo, Toro Negro, and Tortuguero.
2. Dicranopteris pectinata (Willd.) Underw.,
Bull. Torrey Bot. Club 34: 260. 1907.
Fig. 8. F-G
BASIONYM: Mertensia pectinata Willd.
Terrestrial fern. Rhizomes creeping, scabrous,
light brown, with deciduous articulate hairs.
Fronds clambering or decumbent, 1-2 m long,
forming a dense thicket difficult to penetrate;
pinnae unequally bifurcate, with a tuft of rigid,
reddish trichomes in the area of bifurcation, but
without accessory pinnae or these only in the
primary bifurcations; axes cylindrical and brittle,
primary rachis proleptic, with sympodial growth,
tertiary rachis with two narrow longitudinal keels;
leaf segments oblong-deltoid, the secondary
venation 3-5 times bifurcate, the apex retuse, the
margins revolute; lower surface glaucous,
glabrous, or sometimes stellate-pubescent. Sori
yellowish, 0.5-0.7 mm in diameter.
Phenology: Probably found in fertile condition
throughout the year.
Status: Native, very common.
Distribution: Widely distributed in moist
disturbed areas at various elevations. Of wide
distribution in the Neotropics.
Public forests: Carite, El Yunque, Maricao,
and Río Abajo.