Corresponding author: Thien Tam Luong (
Academic editor: Jefferson Prado
A taxonomic revision of the Old-World representatives of the fern genus
Luong TT, Hovenkamp PH, Sosef MSM (2015) Revision of the fern genus Orthiopteris (Saccolomataceae) in Malesia and adjacent regions. PhytoKeys 53: 39–71. doi:
The genus
The question whether
In the Malay-Pacific region, 11
This study was based entirely on herbarium specimens. In total, 240 specimens have been examined from K, L, MICH, MO, NY, SING and additional images or on-line images provided by BM, K, MICH, P, and the JSTOR Global Plants database (plants.jstor.org). Herbarium abbreviations follow
Due to lack of complete specimens, a thorough assessment of the variability of the rhizome morphology was impossible. From the available material, rhizomes can be assessed to be uniformly erect, and radially organized, and may form aerial trunks exceptionally to 1 m high. Characteristically, the vascular system shows two concentric cylinders of meristeles (well-illustrated in
Division and venation of fronds are among the most confusing characters in
Basal pinna of
We define “ultimate segment” as the smallest distal unit with a branched venation around which lamina is incised completely, leaving no or very little lamina around the vein at its base. Margins are described as shallowly incised, crenate, dentate, or deeply lobed, with the degree of dissection quantified, when necessary, by the distance from the base of the shallowest sinuses to nearest costule/vein (Figure
Ultimate segments. Arrows show distance from base of the shallowest sinuses to nearest costule/vein.
The most variable and important characters for distinguishing
Sori of
Different types of soral shapes.
Length of sorus |
equal to width | longer than width |
---|---|---|
Mouth | Funnelform | Narrow funnelform |
Above middle | Wide obovate | Narrow obovate |
At middle | Round/Ovate | Elliptic |
In addition, we use the following descriptive terms:
Outer indusium: (1) symmetric when it is not confluent with the margin but is abruptly set-off from the lamina margin on two sides (Figure
Inner indusium at apex: (1) obtuse-truncate without incision (Figure
Characters of the sporangia are deemed not important for species distinction. Sporangia are stalked with a spherical to hemispherical capsule and a vertical, interrupted annulus with 16–24 indurated cells, which are more or less equal to distinctly unequal in size (Figure
Sporangia of
Rhizome erect, stout, forming a trunk (2–)20–50(–100) cm high, in cross section showing two complete rings of vascular bundles, partly covered with scales, roots inserted on all sides of the rhizome especially in the older parts. Rhizome scales appressed at base, mostly basifix, pseudopeltate to peltate, mostly narrow lanceolate with long attenuate tips, thick, stiff, brittle, dark brown. Fronds tufted, erect, monomorphic. Stipes (10–)30–70(–90) cm long, 0.4–0.8 cm thick (at base), scaly or slightly roughened due to scale traces towards base, greenish-brown. Lamina tri- to quadripinnate, anadromous, deltoid or lanceolate, gradually attenuate towards apex, (30–)100–150(–200) × (30–)40–60(–100) cm, herbaceous to papyraceous, bright-green to brownish–green when dry, abaxial surface sometimes with scattered small scales. Segments alternating, the acroscopic sides of all divisions larger than basiscopic sides, except for the first basiscopic pinnules of the lowest two pinnae; ultimate segments sessile or very short stalked, trapeziform, asymmetric at base, shallowly to deeply lobed. Rachis and costae grooved on adaxial surface, veins dichotomously forked, free. Sori terminal on veins, apical or lateral on the lobe, marginal to sub-marginal, reflexed or not when dry, funnelform, obovate or elliptic, formed by an outer indusium continuous with the lamina and an inner indusium, affixed at sides and usually with same colour as the vein. Sporangia (3–)5–15(–30) per sorus, immersed within indusium when young, exserted when mature. Annulus cells 16–24, more or less equal to distinctly unequal in size. Spores tetrahedral-globose, 25–38 µm in polar view, 20–25 µm in lateral view; perispore surface ornamented with branching sinuous ridges, exospore smooth or weakly scabrate.
Distribution of
Distribution of
1 | Ultimate segments of fronds finely dissected, distance from base of sinuses to the nearest costule 0.1 mm or less; lobes usually with a single unbranched vein, or with 1–2 additional veins |
|
– | Ultimate segments of fronds not finely dissected, distance from base of sinuses to the nearest costule more than 0.1 mm (usually more than 0.5 mm); lobes with veins pinnately branched into more than 3 veins |
|
2 | Ultimate segments completely dissected to the veins, thus forming a single lobe for each vein, lobe not narrowed toward base; sori equal to or wider than the sterile lamina part below its base |
|
– | Ultimate segments not completely dissected to the veins, with 2–3 veins per lobe, lobe narrowed towards base; sori narrower than the sterile lamina part below its base |
|
3 | Sori elliptic-obovate, not reflexed when dried; inner indusium extending into a narrow tongue. Plant including rhizome not more than 1 m tall; stipes slender, 1–2 mm thick |
|
– | Sori funnelform, reflexed when dried, inner indusium extending into a narrow tongue. Plant including rhizome more than 1 m tall; stipes thicker than 2 mm |
|
4 | Outer indusium asymmetric; inner indusium lobed with lobe less than 2/3 width of sorus. Angle between ultimate segment and costa usually larger than 40° |
|
– | Outer indusium symmetric; inner indusium obtuse, if lobed then lobe shallow and more than 2/3 width of sorus. Angle between ultimate segment and costa smaller than 40° |
|
5 | Lamina margin with distinct yellow cartilaginous border; inner indusium extending into a narrow tongue about half the length of the entire sorus; sori elliptic to obovate |
|
– | Lamina margin without distinct yellow cartilaginous border; inner indusium not extending into a narrow tongue, but truncate or with a shallow, obtuse lobe (about 1/4–1/3 length of sorus); sori funnelform |
|
6 | Inner indusium distinctly shorter than outer, if almost equal then lamina thick and finely dissected |
|
– | Inner indusium equal as or little shorter than outer, at least 2/3 as long; lamina thin and not finely dissected |
|
7 | Lamina 140–150 cm wide, as wide as long or wider, papyraceous, thin; ultimate segments stalked, wide trapeziform; veins darker than lamina; sori nearly as wide as long, fertile vein swollen at the joint with base of sori; inner indusium emarginate and irregularly eroded, not lobed |
|
– | Lamina 40–50 cm wide, longer than wide, herbaceous, not thin; ultimate segments sessile or very short stalked, narrow trapeziform; veins lighter than lamina; sori 2/3 as wide as long; fertile vein not swollen at the joint with base of sori; inner indusium entire, forming a shallow lobe. |
|
8 | Abaxial surface of lamina with scattered irregular triangular scales; apex of inner indusium lobed and eroded. Sori situated on both acroscopic and basiscopic sides of lobes |
|
– | Abaxial surface of lamina without scales or with few hair-like scales; apex of inner indusium often entire and obtuse to truncate, if single-lobed then sori situated mostly on acroscopic side of lobes |
|
9 | Sori asymmetric; inner indusium with single lobe; lobe width less than 2/3 width of sorus |
|
– | Sori symmetric, inner indusium obtuse to truncate, if forming a lobe then lobe width at least 2/3 width of sorus |
|
10 | Sori 0.6 mm or more wide |
|
– | Sori not wider than 0.6 mm |
|
11 | Sori strongly reflexed when dry |
|
– | Sori in the plane of the lamina when dry |
|
12 | Lobes of ultimate segments blunt, obtuse; sori longer than wide; outer indusium not confluent with lamina margin on one side but incised |
|
– | Lobules of ultimate segments acute; sori almost as wide as long; outer indusium confluent with lamina margin on one side |
|
PHILIPPINES. Luzon,
(K000794851 [
K000794853 [
K000794864 [
MICH, 1259585 [
non
Type. Jamaica,
Rhizome erect, rising at least 20 cm above ground, diameter 1.5 cm. Rhizome scales pseudopeltate to peltate, 4–7 × 1.0–1.7 mm, narrowly lanceolate, attenuate toward apex. Fronds 100–130 × 40–50 cm; stipes slender, 37–40 cm long, 0.5 –1 cm across (at base), dark brown; lamina deltoid, tripinnate, 70–100 × 40–50 cm, rather thick herbaceous, rigid, brown-green when dry, scaly; pinnae at 40–45° to rachis, largest at base, slightly overlapping, stalked 1 cm, including stalk up to 23–25 × 9–10 cm, lanceolate, first basiscopic pinnules of lowest pinnae enlarged; ultimate segments 0.9–2.0 × 0.3–0.6 cm, sessile or very short-stalked, oblong trapeziform, apex obtuse to acute, margin with weak cartilaginous border; distance from vein to base of sinuses ca. 1.0 mm; crenate-dentate, shallowly to deeply incised, lobes obtuse to acute, veins in lobes 3–15 forks, light to dark brown, not strongly contrasting with lamina, percurrent. Scales on rachis mostly present at base of pinnae or pinnules, irregularly triangular, basifix, 0.7–0.9 × 0.3–0.4 mm.
Sumatra, Peninsular Malaysia (Pahang, Perak, Selangor), Java, Borneo (Sabah, Kalimantan Timur), Philippines (Leyte, Luzon, Mindanao, Negros), Moluccas (Seram), New Guinea, Vanuatu (Aneityum), Fiji (Vanua Levu, Taveuni) (Figure
Terrestrial, mostly in shaded moist habitats, river banks, moist slopes, ravines etc., in primary or disturbed forest, at 0–2000 m altitude.
There are no data that suggest that any of the varieties is distinguished by a different ecology.
Sori protruding from the margin on distinct lobes, in one plane with lamina wings, 0.9–1 × 0.5–0.8 mm, symmetric, narrowly funnelform-obovate, widest at mouth; inner indusium brown, firm, equal to outer indusium, sometimes longer, apex similar to outer indusium; outer indusium truncate or obtuse, shallowly undulate; sporangia 7–12 per sorus, capsule globose and rounded at apex, gradually narrowed toward base, indurated annulus cells 15–20, clearly unequal; spores in polar view 35–45 µm, in lateral view 30–33 µm.
Philippines (Leyte, Luzon, Mindanao, Negros), Moluccas (Seram), Papua New Guinea (Manus).
Although in the shape of inner and outer indusium shape this species resembles
PAPUA NEW GUINEA. Hydrographers Range, alt. 900 m,
Sori not protruding from the margin on distinct lobes, not reflexed when dry, in one plane with lamina wings, 0.7–0.9 × 0.6–0.7 mm, asymmetric, funnelform, widest at mouth of sori; inner indusium bright-brown, firm, usually shorter but not shorter than 2/3 length of outer indusium, apex with c. 0.2 mm long lobe (< 1/3 length of sorus); outer indusium emarginate to undulate-truncate; sporangia 17–21 per sorus, capsule globose and rounded at apex, gradually narrowed toward base, indurated annulus cells 17–20, clearly unequal; spores in polar view 28–32 µm, in lateral view 25–28 µm.
North Moluccas, Papua New Guinea.
PENINSULAR MALAYSIA. Gunong Batu Puteh, August 1885,
Sori protruding from the margin, strongly reflexed when dry, in one plane with lamina wings, 0.9–1.0 × 0.5–0.8 mm, symmetric, narrowly funnelform-obovate, widest just below mouth; inner indusium dark-brown, firm, shorter or equal to outer indusium, apex similar to outer indusium; outer indusium truncate or obtuse, shallowly undulate tip; sporangia 6–12 per sorus, capsule globose and rounded at apex, gradually narrowed toward base, indurated annulus cells 17–20, clearly unequal; spores in polar view 28–30 µm, in lateral view 20–22 µm.
Sumatra, Peninsular Malaysia (Pahang, Perak, Selangor), Java, Borneo (Sabah, Kalimantan Timur), Moluccas (Seram), Papua New Guinea.
This variety is widespread in western Malesia. It is easily recognized when dry by its distinctly protruding and reflexed sori. The ultimate segments of this variety may be the widest among the varieties of
Sori asymmetric, not protruding from the margin, < 0.6 mm wide. outer indusium at one side strongly excurrent on lamina.
SOLOMON ISLANDS. San Cristoval, Hinuahaoro, alt. 900 m, 22 September 1932,
Sori not protruding from the margin, not reflexed, in one plane with lamina wings, 0.8–1.0 × 0.5–0.6 mm, asymmetric, narrow obovate, widest just below mouth sori; inner indusium bright-brown, firm, usually shorter, sometimes equal to outer indusium, apex with 0.1-0.2 mm long lobe; outer indusium deeply emarginate, at one side strongly excurrent on lamina; sporangia 10–15 per sorus, capsule globose and rounded at apex, gradually narrowed toward base, indurated annulus cells 17–22, clearly unequal; spores not seen.
Papua New Guinea (Bougainville), Solomon islands, Vanuatu (Erromango).
The varietal epithet refers to the archipelagic distribution of this taxon.
This variety is quite widespread in the island archipelago stretching from Bougainville to the New Hebrides, but appears to be absent on the mainland of New Guinea.
Lobes of ultimate segments blunt. Sori symmetric, outer indusium truncate, not confluent with lamina margin on one side but incised.
FIJI. Vanua Levu, Taveuni, 29 December 1933,
Lamina not complete for measurement of size and shape, firm-herbaceous, yellowish-green, scales not found; ultimate segments 1.4–1.5 × 0.6–0.7 cm, sessile or very short-stalked, trapeziform, base asymmetric, cuneate, apex obtuse to acute, margin shallowly incised, distance from base of sinuses to costules 0.7–1.5 mm, lobes blunt; veins in lobes 3–15 forks, light to dark brown, not strongly contrasting with lamina, percurrent.
Ultimate segments 1.4–1.5 × 0.6–0.7 cm, sessile or very short stalked, trapeziform, Sori protruding from margin, not reflexed, 0.9–1.0 × 0.8 mm, symmetric, narrowly funnelform, widest at mouth; inner indusium brownish, firm, slightly shorter than outer indusium, apex with 0.2–0.3 mm long lobe, 1/4–1/3 length of sorus; outer indusium truncate, emarginate or undulate; sporangia 10–15 per sorus, capsule globose and rounded at apex, gradually narrowed toward base, indurated annulus cells 17–22, unequal in size; spores not seen.
Vanuatu (Aneityum), Fiji (Vanua Levu, Taveuni).
The varietal epithet refers to the general aspect of the fronds.
The specimens grouped here have been confused with
PAPUA NEW GUINEA. Mount Musgrave, alt. 700 m, 25 June 1889,
Rhizome erect, rising at least 2 cm above ground, diameter unknown. Rhizome scales pseudopeltate, ca. 3.0 × 1.0 mm, lanceolate with long falcate acumen. Fronds 90–110 × 30-50 cm; stipes stout, 35–45 cm long, 0.4–0.5 cm across (at base), light brown; lamina deltoid, tripinnate to quadripinnate, ca. 70 × 30–50 cm, papyraceous, yellow-green when dry, glabrous or with few scattered scales; pinnae at 40–45° to rachis, largest at base, overlapping, stalk 2.0–2.5 cm, including stalk 25–35 × 10–15 cm, lanceolate, first basiscopic pinnules of lowest pinnae enlarged; ultimate segments 1.0–2.0 × 0.5–0.7 cm, sessile or very short stalked, trapeziform, apex acute, margin with weak cartilaginous border; deeply incised to less than 0.2 mm from veins; lobes oblanceolate, veins in lobes unbranched or with 1 fork, light brown and not strongly contrasting with lamina, percurrent. Scales on rachis mostly present at base of segment, hair-like. Sori apical on small lobes, lateral on larger lobes, symmetric, not reflexed, slightly concave with lamina wings slightly recurved, 0.7–0.8 × 0.4–0.5 mm, wide obovate, widest just below mouth, not wider than the lamina below sorus; inner indusium brownish, firm, shorter than outer indusium, apex with c. 0.1 mm long lobe; outer indusium truncate-obtuse.
Papua New Guinea (Boridi).
Terrestrial, at 700–1500 m altitude.
FIJI. Naviti Levu, Dec. 1855,
Rhizome erect, rising at least 2–3 cm above ground, diameter 5–7 mm. Rhizome scales peltate or pseudopeltate, 2.5–3.0 × 0.7–0.9 mm, lanceolate with long falcate acumen. Fronds 30–80 × 10–30 cm; stipes slender, 10–30 cm long, 0.1–0.2 cm across (at base), light brown; lamina deltoid, tripinnate to quadripinnate, 20–50 cm × 10–30 cm, papyraceous, bright green when dry, glabrous; pinnae at 30–35° to rachis, largest at base, overlapping, stalk 0.5 cm, including stalk 15–25 × 6–9 cm, lanceolate, first basiscopic pinnules of the lowest pinnae enlarged; ultimate segments 1–2 × 0.5 cm, sessile or very short stalked, trapeziform, apex acute, margin without or with very weak cartilaginous border; deeply incised to less than 0.1 mm from veins; lobes narrowly oblanceolate, veins in lobes unbranched, light brown and not strongly contrasting with lamina, ending well below apex. Scales on rachis mostly at base of pinnae or pinnule, irregular triangular, basifixed. Sori apical on lobes, symmetric, not reflexed when dried, in one plane with lamina wings, 0.7–1.0 × 0.4–0.5 mm, elliptic, widest at middle or slightly above, wider than the sterile lamina below sorus; inner indusium brownish green, thin and slightly transparent, usually shorter, sometimes equal to outer indusium, apex with narrow 0.2–0.3 mm long tongue, c. 1/2 length of sorus; outer indusium obtuse; sporangia 4–7 per sorus, capsule globose and rounded at apex, gradually narrowed toward base, indurated annulus cells 16–18, ±equal; spores in polar view 26–30 µm, in lateral view 20–25 µm.
endemic to Fiji (Viti Levu).
Terrestrial in dense forest, bank of creek, at 50–1200 m altitude.
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.
New Caledonia; New Hebrides (?), Fiji (?)
Terrestrial on slopes or margin of humid montane forest, at 300–900 m altitude.
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
MADAGASCAR. Antananarivo,
Rhizome erect, rising at least 5 cm above ground, diameter 1.5–2 cm. Rhizome scales pseudopeltate–peltate, 1.5–3.0 × 0.5–1.3 mm, narrow lanceolate with long sinuose acumen, thick. Fronds 110–150 × 100–150 cm (length fairly equal with width); stipes slender, 30–50 cm long, 0.4–0.6 cm across (at base), dark brown; lamina rhomboid–deltoid, widest at 3–5 cm above the base, tripinnate to quadripinnate (lowest lobe of ultimate segments free or nearly so), 60–110 × 140–150 cm, papyraceous, thin, dull brown–yellowish green when dry, glabrous; pinnae at 45–50° to rachis, largest at the second from base, overlapping, stalk 3 cm, including stalk 30–50 × 10–15 cm, lanceolate, first acrosopic, sometimes first basiscopic pinnule of the lowest pinnae enlarged; ultimate segments 3–5 × 1.5–2.5 cm, 1–2 mm stalked, ovate-trapeziform, with strongly asymmetric base, lowest lobe almost completely separated, apex obtuse, margin with weak cartilaginous border; shallowly incised to 1.5–2.5 mm from veins; lobes rounded, veins in lobes 8–9 forks, dark brown, not contrasting with lamina, percurrent. Scales on rachis a few hair-like scales only on veins (few scales on an entire frond), hair-like. Sori lateral on lobes, symmetric, not reflexed, sometimes concave with lamina wings recurved, 0.8–1.1 × 0.5–1.0 mm, wide funnelform-obovate, sometimes narrow funnelform, widest at mouth or just below mouth; inner indusium dull brown, papyraceous, thin but tough, with swollen joint at base with distinct dark line at the joint, 1/2 – 2/3 as long as outer indusium, apex emarginate and irregularly eroded, not extending into a lobe; outer indusium truncate to obtuse; sporangia 10–17 per sorus, capsule globose and rounded at apex, gradually narrow edtoward base, indurated annulus cells 18–24, unequal in size; spores in polar view 30–38 µm, in lateral view 22–25 µm.
endemic to Madagascar (Toamasina, Antsiranana, Toliara, Tamatave, Antananarivo).
Terrestrial in moist, shady, evergreen forest, on laterite soil derived from gneiss or in lowland dense disturbed forest with bamboo and
Differs from all other
SAMOA. Savai’i, 31 December 1905,
Rhizome erect, rising at least 50 cm above ground, diameter unknown. Rhizome scales unknown. Fronds 150–200 cm (complete fronds not seen); stipes stout, ca. 70 cm long, 0.5–0.8 cm across (at base), light brown; lamina probably deltoid, quadripinnate, 100–150 cm long, at least 60 cm wide, firm- herbaceous, brownish green when dry, scaly with scattered scales on abaxial surface, denser at base of segments, and on veins and base of rachis; pinnae at 45–50° to rachis, separated or slightly overlapping, stalk 1.6 cm, including stalk up to 30–45 × 15–20 cm, lanceolate; ultimate segments 1.0–2.0 × 0.4-0.8 cm, sessile or very short stalked, narrowly trapezoid, apex obtuse to acute, margin with weak cartilaginous border; shallowly incised to 0.3-1.0 mm from veins; lobes obtuse to acute, veins in lobes form 3–6 forks, yellow green, weakly contrasting with lamina, percurrent. Scales on rachis irregularly triagular, basifixed, 0.4–1.4 × 0.4–0.9 mm. Sori lateral on lobes, symmetric, not reflexed, in one plane with lamina wings, 0.5–0.8 × 0.6–0.75 mm, suborbicular to funnelform, widest at mouth; inner indusium brown to dark brown, firm, slightly shorter or equal to outer indusium, rarely longer, apex with a rounded to truncate, 0.1–0.2 mm long lobe, eroded, ca. ¼ length of sorus; outer indusium truncate, shallowly lobed or eroded; sporangia 5–10 per sorus, capsule globose and rounded at apex, gradually narrowed toward base, indurated annulus cells 17–19, clearly unequal; spores in polar view 30–33 µm, in lateral view 23–27 µm.
endemic to Samoa (Upolu, Savaii).
Terrestrial, medium wet forest, at 600–900m altitude
The specific epithet refers to the type locality.
The key character to separate this newly recognised species from the others are the many scales covering the abaxial surface of lamina.
FIJI.
Rhizome erect, rising at 5–60 cm above ground, diameter 1.5–10 cm. Rhizome scales pseudopeltate, 4–8 × 0.7–1 mm, narrow, linear lanceolate, usually falcate and suddenly contracted into a long thin acumen. Fronds 100–170 × 40–50 cm; stipes slender, 30–70 cm long, 0.3–0.8 cm across (at base), dark brown; lamina deltoid, widest at base, tripinnate, sometimes quadripinnate in large plants, ca. 70 × 40 cm, herbaceous, lively green when dry, glabrous; pinnae at 35–45° to rachis, largest at base, separated or slightly overlapping, stalk 1–2 cm, including stalk up to 26 × 12 cm, lanceolate, first basiscopic pinnules of lowest pinnae enlarged; ultimate segments 1.5–2.0 × 0.7–1.0 cm, sessile or very short stalked, trapezoid to narrowly so near frond apex, apex obtuse to acute or attenuate, margin with weak cartilaginous border; shallowly to deeply incised to 0.2–2.0 mm (see discussion) from veins; lobes acute, veins in lobes with 1–3 forks, bright green, strongly contrasting to the lamina, percurrent, sometimes ending just below apex. Scales on rachis absent, absent. Sori apical on small lobes, lateral on larger lobes, asymmetric, sometimes symmetric, not reflexed, in one plane with lamina wings, ca. 1.5 × 1 mm, funnelform, sometimes ovate, widest at middle to 2/3 from base; inner indusium yellow bright green, contrasting in colour with lamina, firm, 1/2–2/3 as long as outer indusium, apex with obtuse to acute lobe, slightly eroded, ca. 0.25–0.5 the length of inner indusium; outer indusium obtuse, sometimes acute, truncate or emarginate with 1–2 shallow sinuses; sporangia 7–10 per sorus, capsule globose and rounded at apex, gradually narrowed toward base, indurated annulus cells 17–22, ±equal; spores in polar view 30–35 µm, in lateral view 25–27 µm.
Endemic to Fiji (Viti Levu, Vanua Levu, Ovalau).
Terrestrial, dense forest, bank along stream, at 0–1000 m altitude.
This species is highly variable in terms of frond dissection, and sorus shape. Plants from higher altitudes (above ca. 500 m) have larger fronds and furthermore differ from the lowland plants in ultimate segments being deeply incised (distance of lamina from base of sinuses to costules less than 0.5 mm), and sori with almost equally long inner- and outer indusium. In contrast, the lowland plants have ultimate segments more shallowly incised (distance of lamina from base of sinuses to costules more than 0.5 mm), and sori with a large difference in length between inner and outer indusia. We could not separate the two forms because of the presence of intermediate specimens.
PAPUA NEW GUINEA. Idenburg River, 15 km southwest of Bernhard camp, alt.1800 m, 1939,
Rhizome erect. Rhizome scales not seen. Fronds 120–160 × 40–50 cm; stipes stout, 40–50 cm long, 0.4–0.6 cm across (at base), dark brown; lamina deltoid, widest at base, tripinnate to quadripinnate, 100–120 × 40–50 cm, herbaceous, dark brownish green when dry, glabrous or with few scattered scales; pinnae at 30–35° to rachis, largest at base, overlapping, stalk 0.5 cm, including stalk 15–25 × 6–9 cm, lanceolate, first basiscopic pinnules of lowest pinnae enlarged; ultimate segments 1.0–1.5 × 0.5 cm, sessile or very short stalked, trapezoid, apex acute, margin with weak cartilaginous border; almost completely dissected to less than 0.2 mm from veins; lobes narrowly oblong, veins in lobes unbranched or with 1 fork, dark brown and not contrasting with lamina, percurrent. Scales on rachis mostly at base of pinnae or pinnule, very few on veins, hair-like. Sori lateral or apical on lobes, symmetric, slightly reflexed, slightly concave with lamina wings slightly recurved, 1.0–1.2 × 0.6–0.7 mm, funnelform, widest at mouth, not wider than the sterile lamina below sorus; inner indusium dull brown, firm, 4/5–2/3 as long as outer indusium, apex truncate; outer indusium truncate; sporangia 7–12 per sorus, capsule globose and rounded at apex, gradually narrowed toward base, indurated annulus cells 16–20, ±equal; spores in polar view not studied, in lateral view.
Papua New Guinea (Idenburg River).
Distribution of
Terrestrial in bottom of ravines, rain forest, at 1800 m altitude.
This species can be mistaken for
Type.
=
Both names
We would like to thank many botanists in Leiden Herbarium for their support and nomenclatural advice. We are grateful to K, MO, MICH, NY, SING for the loan of collections. We thank Dr. Stuart Lindsay for the language check, and three reviewers for their constructive comments.
Identification list Orthiopteris
† Deceased