Polypodium aculeatum L.
Aspidium aculeatum (L.) Sw.
Dryopteris aculeata (L.) Kuntze
Polypodium lobatum Huds.
Dryopteris setifera (Forssk.) Woyn. ex Schinz & Tell. subsp. lobata (Huds.) Maire

Hard shield fern.

Rhizome erect, branching, stout. Fronds 60 x 14 cm, evergreen, monomorphic, blade/stipe ratio: 5:1. Stipe grooved, mixed large and small reddish-brown scales, smaller and narrower upwards to hair-like at the top of the rhachis. Lamina 2-pinnate, juveniles less, more divided closer to the rhachis and closer to the base, lanceolate in outline, glossy, leathery, dark green, hairless above, a few sparse hairs or scales below. Rhachis and costa with linear to lanceolate scales. Pinnae 25 to 40 pair, subopposite, lowest pinnae half the length of the middle ones, pinnae generally curving upward; pinnules adnate to the pinnae, the first pinnule on the upper side generally larger than the others; all pinnules have an outward-pointing spiny-tipped lobe at the base, curved towards the pinna apex; costae grooved above, not continuous with rhachis; margins very spiny; veins free, forked. Sori round, in 1 row on each side of the costa between midrib and margin on the upper half of the blade; indusium peltate, shriveling upwards like an inverted umbrella, but persistent, central.

aculeatum: prickly, referring to the margins of the pinnules.

Uplands, rocky outcrops, on limestone.

Europe, Africa and perhaps eastward to the Himalayas, Japan, Taiwan.

Algeria, Morocco and Western Sahara.

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