Orthiopteris henriettae (Baker) Copel., Gen. Fil.: 50. 1947.

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 : 55-56

5. Orthiopteris henriettae (Baker) Copel., Gen. Fil.: 50. 1947. Figs 2h , 3q, r, s , 5a , 6f

Dicksonia henriettae Baker in Hook. & Baker, Syn. Fil. (ed. 2): 462. 1874.

Microlepia henriettae (Baker) Kuhn, Reisen Ost-Afrika (Decken): 62. 1879. Type. Based on Dicksonia henriettae Baker

Dennstaedtia henriettae (Baker) Diels, Nat. Pflanzenfam. 1: 4: 218. 1899. Type. Based on Dicksonia henriettae Baker

Saccoloma henriettae (Baker) C.Chr., Dansk Botanisk Arkiv 7: 75, t. 25, f. 12-13. 1932. Type. Based on Dicksonia henriettae Baker

Ithycaulon henriettae (Baker) C.Chr. Index Filic., Suppl. III: 116. 1934. Type. Based on Dicksonia henriettae Baker

Type.

MADAGASCAR. Antananarivo, Baker s.n. (holo: K, 000351013* [http://specimens.kew.org/herbarium/K000351013]).

Description.

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.

Distribution.

endemic to Madagascar (Toamasina, Antsiranana, Toliara, Tamatave, Antananarivo).

Ecology.

Terrestrial in moist, shady, evergreen forest, on laterite soil derived from gneiss or in lowland dense disturbed forest with bamboo and Acanthaceae , border of the creek etc., at 350-1700 m altitude.

Discussion.

Orthiopteris henriettae is the only representative of the genus in Madagascar, where it is not rare. It is clearly distinct from the Malay-Pacific species by its fronds having a papyraceous and thin texture, the ovate-trapeziform ultimate segments with shallowly crenate-dentate margin and usually swollen joints in the veins just below sori. The ultimate segments seem to be narrower in collections from higher altitudes.

Figures

Figure 2. Ultimate segments. Arrows show distance from base of the shallowest sinuses to nearest costule / vein. a Orthiopteris ferulacea, Smith 8932 (K) b Orthiopteris cicutarioides, Carr 13257 (K) c Orthiopteris samoensis, Reinecke 97 a (L) d Orthiopteris trichophylla, Brass 12239 (L) e Orthiopteris campylura var. cautada, Carr 12518 (L) f Orthiopteris campylura var. laxa Mueller s. n. (L) g Orthiopteris campylura var. kingii, Brass 12941 (MICH) h Orthiopteris henriettae, Lam & Meeuse 5892 (L) i Orthiopteris campylura var. insularis Braithwaite 4110 (L). All scale bars 1 mm.

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 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.