Calciphilopteris Yesilyurt & H.Schneider, 2010

Yesilyurt, Jovita C. & Schneider, Harald, 2010, The new fern genus Calciphilopteris (Pteridaceae), Phytotaxa 7, pp. 52-59 : 53-55

Calciphilopteris Yesilyurt & H.Schneider , gen. nov. — Figs. 1A–C

Calciphilopteris gen. nov. Doryopteridis affinis sed rhizomate breviter vel longe repenti, paleis rhizomatum lanceolatis vel anguste lanceolatis clathratis vel semiclathratis, petiolo tereti fasciculum vascularem unum tantum continenti, petiolo laminaque fibrillas (pilos squamiformes) atque squamas non clathratas vel semiclathratas ferentibus, sporangio plerumque longipedicellato 32 sporas continenti, plantis plerumque rupicola locus calcareos incolentibus differt.

Type species:— Calciphilopteris ludens (Wall. ex Hook.) Yesilyurt & H.Schneid. = Pteris ludens Wallich ex. Hooker (1858: 210). Holotype: INDIA: Wallich 88 (K).

Plants terrestrial or rupicolous; essentially growing on limestone. Rhizome slender, short- to long-creeping, scales up to 3 mm, linear to ovate-lanceolate, acuminate to caudate, predominantly bicoloured, with clathrate to semi-clathrate centre, and paler, narrow to broad border, margin entire to dentate towards the apex. Petiole terete to slightly sulcate (towards) at the base of the lamina; one vascular bundle; dark brown, atropurpureous to black, base with scales as those of the rhizome, higher up the petiole with indumentum (generally dense towards the base of the lamina) usually scaly, scales semi- to non-clathrate, with fibrils, rarely with white hairs or glabrous. Sterile and fertile fronds dimorphic (architecture of fertile lamina more complex), sub-coriaceous to coriaceous; glabrescent to glabrous, indumentum on the abaxial side with glandular hairs and/or fibrils and non-clathrate scales at the base of the lamina; veins anastomosing, without included free veinlets. Sterile fronds up to 45 cm; lamina up to 17 cm, ranging from simple, entire or 3-lobed to pedate; oblong-oval, cordate, sagittate, hastate, lobed to pentagonal in outline; pinnae/segments1–2(–4) pairs; the margins usually with a whitish or brown cartilagineous border, entire; hydathodes generally present on the upper surface; veins ending free near the margin (occasionally confluent in C. allenae ); basal pinnae lobed basiscopically or not. Fertile fronds up to 65 cm; lamina up to 20(–25) cm; sagittate, hastate, pentagonal to broad-cordate or suborbicular in outline, 3-lobed to pedate, pedate-pinnatifid (pedate-2-pinnatifid); pinnae/segments 2–5(–6) pairs; ascending to patent, deltoid to long-lanceolate, acute or acuminate, predominantly with entire margins; basal pinna/segment with acroscopic and/or with basiscopic segments/lobes; first segment/lobe divided or not, falcate to lanceolate. Sori marginal, usually on a continuous vascular commissure (connecting the vein-tips), rarely interrupted at sinuses, covered by a continuous modified marginal indusium, without paraphyses; receptacle and indusium continuous, including in the sinuses; indusium with margin entire to slightly eroded. Sporangium with pedicel 1–2(–2.5) times the capsule length; capsule without basal cell; annulus with 17–34 indurate cells; with 32 spores per sporangium. Spores trilete, tetrahedral to globose, echinate or cristate, without equatorial flange. Chromosome number n = 29, 30 or multiples thereof.

Distribution:—Southeast Asia, from Indo-China to New Guinea (and Australia).

Habitat & Ecology:—exclusively on limestone outcrops.

Etymology:—the genus name is a composite from the Greek calx (limestone), philus (loving) and pteris (fern) and emphasizes the exclusivity of limestone outcrops as the natural habitat for this fern.

Diagnostic key to the species of Calciphilopteris

1. Basal pinna/segment with 2–4 basiscopic segments, all ascendant; first basiscopic segment with 1–3 lobes ( Fig. 1B ), conspicuous or not, ascendant; sinus (between pinnae/segments) usually narrow, acute or round (seldom slightly rectangular); fertile lamina pedate-pinnatifid to pedate-2(–3)-pinnatifid, broadly ovate to cordate-ovate, pinnae/segments 3–7 ( Fig 1A ), all equally ascendant, long lanceolate to linear lanceolate (except basal pinna) ........ C. papuana

- Basal pinnae/segment with 1–3 basiscopic segments, ascendant or not; first segment very rarely lobed; sinus (between pinnae/segments) rounded to slightly rectangular; fertile lamina pedate to pedate-pinnatifid, hastate to trilobed, ovate-lanceolate, slightly pentagonal or obovate, pinnae/segments 1–4, all equally ascendant or not, usually lanceolate (except basal one) ........................................................................................................................................ 2

2. Scales of rhizome and base of petiole long lanceolate to linear lanceolate, caudate, margin (half way towards apex) dentate; fertile lamina generally sagittate to trilobed (rarely pedate), hydathodes absent; marginal veins regularly anastomosing along the leaf margin ............................................................................................................. C. alleniae

- Scales of rhizome and base of petiole lanceolate to long lanceolate, not caudate, margin (half way towards apex) remotely dentate to entire; fertile lamina hastate, pedate to pedate-bipinnatifid, hydathodes present (sometimes obscure); marginal veins ending free along the leaf margin ......................................................................................... 3

3. Basal pinnae with acroscopic and basiscopic segments; scales margin (half way towards apex) entire; fertile lamina commonly pedate-pinnatifid to pedate-2-pinnatifid, pentagonal, pinnae/segments 2–4, all equally ascendant; basal pinna/segment with 1(–2) acroscopic segment and 2–3 basiscopic segments/lobes ( Fig. 1A ), all ascendant; first basiscopic segment/lobe generally unlobed .......................................................................................................... C. ludens

- Basal pinnae with acroscopic pinnae only; scales margin (half way towards apex) dentate to occasionally dentate; fertile lamina commonly hastate to pedate (pedate-pinnatifid), ovate-lanceolate, slightly pentagonal, pinnae/segments 1–2(–3), basal pinna/segment ascendant, other segments/lobes patent to slightly ascendant; basal pinna/segment with 1(–2) basiscopic segment/lobe, which is usually unlobed and generally parallel to the petiole ( Fig. 1C ) ... .................................................................................................................................................................. C. wallichii

Figures

FIGURE 1. Sketches of fertile leaves showing their general attributes and morphological variation: A. Calciphilopteris ludens. B. Calciphilopteris papuana. C. Calciphilopteris wallichii.