Tectaria gemmifera (Fée) Alston

Dryopteridaceae, JP Roux, M Shaffer-Fehre, B Verdcourt. Flora of Tropical East Africa. 2007

Type

Madagascar, ‘habitat in insula Madagascariens’, Pervillé s.n. (missing)

Morphology General Habit

Terrestrial.

Vegetative Multiplication Rhizomes

Rhizome to 13 cm high, 2 cm in diameter, with dark brown lanceolate scales 5–10 × 1 mm, with pale borders.

Morphology Leaves

Fronds in tufts of 4–9, to 1.8 m long. Veins and veinlets anastomosing; free included veinlets in most areoles but absent along the rachis and rare in the triangular areoles between rachis and costa; small glandular hairs ± 0.5 mm long thinly scattered on axes from rachis to costa, denser at pinna base and pinna margins where it is decurrent between pinna segments, on sinus margin and adaxially, above sinus, on rachis, pinna costa and costa, resembling velvet; minute scales sometimes present in central areoles

Morphology Leaves Stipes

Stipe pale brown, 70–72 cm long, 5 mm in diameter at base, adaxially grooved, glabrous when mature, basal 3–5 cm covered in scales similar to those of rhizome.

Morphology Leaves Leaf lamina

Lamina membranous to coriaceous, dark green, deltoid-pentagonal, 45–100 × 30–80 cm, 3pinnatifid.

Morphology Leaves Pinnae

Gemmae sometimes present at pinnae bases or along pinnae costa, on both surfaces Pinnae in 4–6 pairs, basal pinna pair the longest and stalked, terminal segment pinnatifid; pinnules to 18 cm long, the basal the largest, divided in up to 10 secondary pinnules; ultimate segments oblong, falcate, with crenate margins.

Morphology Reproductive morphology Sori

Sori inframarginal to median, in up to 4 pairs per segment, 0.5–2(–3) mm in diameter; indusium small, reniform, minutely ciliate

Morphology Reproductive morphology Spores

Spores pale brown, monolete, perispore winged, cristate

Figures

Figure 1: 8-11, figure 2:5

Ecology

Moist forest, especially near streams, also in gallery forest; terrestrial, occasionally in rock crevices; may be locally common; 600–2550 m

Conservation

Widespread; least concern (LC)

Note

Sori of fertile specimens of T. gemmifera vary from barely 0.5 mm diameter (gemmae present) to almost 3 mm diameter (gemmae absent); the precociously fertile or, indeed, sterile specimens will almost always be covered by the largest (7 mm in diameter) or the most numerous (to 25 in Pirozynski P104) gemmae; i.e. a large physiological debt arises to account from the production of gemmae; but only one 5 mm gemma and a fully sporipherous blade in Thomas 1498. In the presence of gemmae sori will occasionally develop only in segments near tips of pinnules. From the point of reproduction, large sori in the absence of gemmae or many gemmae on sterile or precociously fertile fronds, may offer an equal chance of creating progeny. An increased dissection of the blade can carry a larger number of gemmae. A caution must be sounded to check gemmae closely. Due to occasional infestation by psychids (Psychideae, insects) specimens have been wrongly identified as T. gemmifera. Psychids coat their coccoon with “locally available” materials. On fern blades spores serve this purpose. As the larva clings to the vascular supply, a thick coat of spores is sometimes mistaken for a gemma. In the literature ‘white hairs’ are mentioned with the indumentum; during this survey they were observed just once ( Pirozynski P104), a fine down of white, septate hairs (lost early) arranged regularly, following the vascular system and admixed with stout glandular cells.

Distribution

Range: Congo-Kinshasa, Rwanda, Burundi, Angola and south to South Africa; Madagascar, ?southeast Asia Flora districts: U1 U2 U3 U4 K1 K3 K4 K5 K6 K7 T2 T3 T 4 , T6 T7 T8

Use

None recorded