Orthiopteris campylura var. laxa P.H.Hovenkamp & T.T.Luong, 2015

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 : 50-51

e. Orthiopteris campylura var. laxa P.H.Hovenkamp & T.T.Luong var. nov. Figs 2f , 3o, p

Diagnosis.

Lobes of ultimate segments blunt. Sori symmetric, outer indusium truncate, not confluent with lamina margin on one side but incised.

Type.

FIJI. Vanua Levu, Taveuni, 29 December 1933, A.C. Smith 865 (holo: NY).

Description.

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.

Distribution.

Vanuatu (Aneityum), Fiji (Vanua Levu, Taveuni).

Etymology.

The varietal epithet refers to the general aspect of the fronds.

Discussion.

The specimens grouped here have been confused with Orthiopteris firma mainly because of the similarity in the lobed inner indusium, but differ from that species in sorus shape and a less distinct cartilaginous border. The two available specimens examined here also show a considerable variation among themselves. More specimens or molecular evidence are needed to provide better support for the existence of this new variety.

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.