Orthiopteris firma (Kuhn) Brownlie, Fl. Nouv.- Caledonie & Depend . 3: 112, t. 13, f. 9, 10. 1969.

Luong, Thien Tam, Hovenkamp, Peter H. & Sosef, Marc S. M., 2015, Revision of the fern genus Orthiopteris (Saccolomataceae) in Malesia and adjacent regions, PhytoKeys 53, pp. 39-71 : 53-54

4. Orthiopteris firma (Kuhn) Brownlie, Fl. Nouv.- Caledonie & Depend. 3: 112, t. 13, f. 9, 10. 1969. Figs 3m, n , 4c , 5b , 6a, b

Saccoloma moluccanum var. firmum Kuhn, Verh. Zool.-Bot. Ges. Wien 19: 582. 1869.

Saccoloma firmum (Kuhn) C.Chr., Vierteljahrsschr. Naturf. Ges. Zürich 70. 221. 1925. Type. Based on var. firmum Kuhn

Ithycaulon firmum (Kuhn) C.Chr., Index Filic., Suppl. III: 116. 1934. Type. Based on var. firmum Kuhn

Lectotype

(here designated). VANUATU. Erromango, MacGillivray s.n (B, 200157508 [http://herbarium.bgbm.org/object/B200157508]).

Description.

Rhizome erect, rising at least 20 cm above ground, diameter unknown (complete rhizome not seen). Rhizome scales basifixed, round to lanceolate, round scales 0.5-0.85 × 0.6-1.0 mm, cordate scales 1.2-1.5 × 1.1-1.5 mm, lanceolate scales 0.7-0.8 × 0.-2.5 mm. Fronds ca 100-150 cm long; stipes stout, of unknown length, ca. 0.7-0.8 cm across (at base), dark brown; lamina deltoid, quadripinnate, complete fronds not seen, herbaceous, thick, dark green when dry, glabrous; pinnae at 50-60° to rachis, largest at base, separated or slightly overlapping, stalk 3 cm, including stalk up to 40 × 25 cm, lanceolate, first basiscopic pinnules of lowest pinnae enlarged; ultimate segments 2.0-3.0 × 0.7-1.5 cm, sessile or very short stalked, narrow trapeziform, apex obtuse to acute, margin with distinct, thick, yellow cartilaginous border; shallowly incised to 1.0-2.0 mm from veins; lobes acute, veins in lobes 7-15 forks, bright green, clearly visible and contrasting with lamina, percurrent, joining with border. Scales on rachis only on rachis or veins, very sparse (few scales on an entire frond), irregular triangular, basifixed, 0.35-0.50 × 0.25-0.4 mm. Sori apical on small lobes, lateral on larger lobes, symmetric, not or slightly reflexed, slightly concave with lamina wings usually recurved, 1.4-1.2 × 0.8 mm, elliptic to narrowly obovate, widest at middle to 3/4 from base; inner indusium bright brown and contrasting in colour with lamina, firm, slightly shorter than outer indusium, sometimes equal, apex with narrow 0.35-0.45 mm long tongue, 1/3-1/2 length of sorus; outer indusium acute, obtuse, rarely truncate or emarginate; sporangia 9-15 per sorus, capsule rectangular-triangular with truncate apex, narrowed toward base, indurated annulus cells 17-20, unequal; spores in polar view 30-32 µm, in lateral view 25-27 µm.

Distribution.

New Caledonia; New Hebrides (?), Fiji (?)

Ecology.

Terrestrial on slopes or margin of humid montane forest, at 300-900 m altitude.

Discussion.

This species is quite large and therefore often incompletely represented in collections. Rhizomes are usually missing and entire fronds are not preserved. The brightly colored, firm and large sori are very conspicuous on the dark green lamina. The majority of the specimens of Orthiopteris firma are from New Caledonia, except for the two specimens cited in the protologue and a single specimen from Fiji (Betche s.n.). All these represent records more than 100 years old for each respective location (collecting date is neither mentioned in literature nor indicated on specimen labels but collectors lived before 1913). For at least one of these specimens, a mistake in labelling is likely, as a similar specimen (MacGillivray s.n. B 200157509) is indeed labelled as originating from New Caledonia. All recent collections of Orthiopteris firma are from New Caledonia, and therefore Orthiopteris firma is best considered as an endemic for New Caledonia.

Kuhn (1869) described Saccoloma moluccanum var. firma based on two specimens: Herus 85 (Aneityum, New Hebrides) and MacGillivray s.n. (Erromango, New Hebri des, B200157508). Our study concludes that they belong to different taxa. Herus 85 is Orthiopteris campylura var. laxa , MacGillivray s.n. is this taxon, although probably with an erroneous location, and is here selected as the lectotype for Saccoloma moluccanum var. firmum to maintain nomenclatural stability.

Figures

Figure 3. Sori of Orthiopteris seen from abaxial side. a, b Orthiopteris campylura var. campylura (Cuming 119, MICH) c Orthiopteris campylura var. kingii (Brass 12941, MICH) d Orthiopteris trichophylla (Brass 12239, L) e Orthiopteris tenuis (Smith 9154, L) f Orthiopteris tenuis (Smith 7274, L) g Orthiopteris campylura var. caudata (Carr 12518, L) h Orthiopteris cicutarioides (Carr 13257, K) i, j Orthiopteris campylura var. insularis (Braithwaite 4110, L) k Orthiopteris tenuis (small segment) (Degener 14648, L) l Orthiopteris ferulacea (Smith 8932, K) m, n Orthiopteris firma (Schlechter 14890, L) o, p Orthiopteris campylura var. laxa (Mueller s. n., L) q, r Orthiopteris henriettae (Lam & Meeuse 5892, L) s Orthiopteris henriettae. t Orthiopteris samoensis (Reinecke 97 a, L) u, v Orthiopteris samoensis (Vaupel 312, L). All scale bars 1 mm, oi = outer indusium, ii = inner indusium.

Figure 4. a-d Rhizome scales and e-h rachis scales of Orthiopteris. a Orthiopteris cicutarioides (Carr 13257, L) b Orthiopteris ferulacea (Smith 8932) c Orthiopteris firma (Green 1793, K) d Orthiopteris campylura var. kingi (Hoogland & Craven 10162, L) e, f Orthiopteris campylura var. kingi (Larhing 6910, L) g, h Orthiopteris samoensis (Reinecke 97 a, L). Scale bars: 1 mm (a-d), 0.1 mm (e-h).

Figure 5. Sporangia of Orthiopteris, note the unequal-sized annulus cells. a Orthiopteris henriettae (Malcomber et al. 2246, MO) b Orthiopteris firma (Green 1793, K). All scale bar 0.1 mm.

Figure 6. Orthiopteris spores. a, b Orthiopteris firma (Guillaumin & Baumann-Bodenheim 10318, L) c Orthiopteris tenuis (Smith 9154, L) d Orthiopteris campylura var. campylura (Elmer 11717, L) e Orthiopteris campylura var. caudata (Ridsdale 30654, L) f Orthiopteris henriettae (Lam & Meeuse 5892, L) g, h Orthiopteris samoensis (Sledge 1563, L). All scale bars 10 µm.