ferns and allied plants - Department of Land Resource Management ...

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FERNS and ALLIED PLANTS
dichotomies; the shorter primary rachis branches, alternate, and terminating with a hairy dormant apex,
each bearing a pair of pinnate, bipinnate, or tripinnate leaves; fertile and sterile leaflets similar or
dissimilar; leaflets distinctly stalked or palmatilobate or pinnatilobate, sometimes jointed at base of
laminal portion. Sporangia borne separately in 2 rows on marginal lobes of the fertile leaflets, each near a
vein ending and covered with an indusium. Spores tetrahedral-globose.
A monogeneric family consisting of 30 species widespread in the tropics and subtropics. Four species
occur in Australia, two in the D.R.
Taxonomic references: Andrews (1990); Chinnock (1998c).
LYGODIUM Sw.
1 Pinnule stalks of similar length ................................................................................... L. microphyllum
1: Pinnule stalks decreasing in length distally ............................................................... 2
2 Fertile fronds with basal pinnules bipinnate ............................................................ L. flexuosum
2: Fertile fronds with basal pinnules tripinnate ............................................................ L. japonicum
Chinnock (1998c) reported L. japonicum from the general Darwin area. Records of this species at DNA
indicate that it was collected from the coastal vine forest adjacent Lameroo Beach, Darwin. It is
believed to be a garden escape and is not treated further.
L. flexuosum (L.) Sw.
Ophioglossum flexuosum L.
Rhizome short-creeping. Juvenile fronds once-forked.
Climbing rachis wiry, subterete, flattened on one
side with ridged edges, glabrous or sparsely
pubescent. Primary rachis branches 0.5–4 mm long.
Secondary rachis flattened and winged along upper
side; sterile frond pinnate, fertile frond bipinnate
at base; petiolules of leaflets decreasing in length
distally, with distal leaflets appearing sessile. Basal
leaflets of sterile frond palmate with up to 7 lobes,
lateral leaflets (obscurely) 3-lobed, terminal leaflet
(irregularly) palmately lobed. Sterile leaflets 12.5–
64 mm long, 4.5–10.5 mm wide, chartaceous;
(obliquely) ovate-lanceolate to triangular; base
truncate to cuneate; margins serrulate; veins free.
Fertile leaflets 8–78 mm long, 9–12 mm wide.
Sporogenous lobes 0.5–7.5 mm long. Fertile plants:
all year.
Fig. 8 (Tindale 10056; van Oertzen, DNA 145121);
Pl. 7 (unvouchered).
India, Sri Lanka, Malesia and Australia (W.A.,
N.T., Qld). In the N.T. common in the Top End
north of latitude 16° S. Associated with monsoon
forests on scree slopes close to water.
L. microphyllum (Cav.) R. Br.
Ugena microphylla Cav.
Rhizome long-creeping. Juvenile fronds once-forked.
Climbing rachis wiry subterete, flattened on one
side occasionally with ridged edges, glabrous or
sparsely pubescent. Primary rachis branches 1–
10 mm long. Secondary rachis flattened and winged
along upper side; sterile frond pinnate, fertile
frond pinnate, rarely bipinnate at base; petiolules
of leaflets of similar length. Basal leaflet of sterile
frond (3-) or 4-lobed, lateral leaflets (obscurely)
3-lobed, terminal leaflet (irregularly) palmately
lobed. Sterile leaflets 9–63 mm long, 4–22 mm
wide, membranous to chartaceous; laminal
portions deciduous, (obliquely) ovate-lanceolate
to triangular; base cordate, truncate to cuneate;
margins finely or often obscurely crenulate; veins
free. Fertile leaflets 9–55 mm long, 4–22.5 mm
wide. Sporogenous lobes 0.5–17.5 mm long. Fertile
plants: all year. Climbing Maidenhair.
Fig. 8 (Must 1641); Pl. 8 (unvouchered).
Native to tropical Africa, south-east Asia,
Malesia and Australia (W.A., N.T., Qld, N.S.W.)
and an invasive weed in southern Florida, U.S.A.
In the N.T. it is found north of latitude c. 19° S.
A commonly collected fern associated with
wetlands or monsoon vine thickets fringing
springs, creeks or rivers.
Some individuals are dormant over the dry season
persisting by their subterranean rhizomes.
FDRV1 March 2011