TABLE 1. Morphological comparison of Asplenium atlanticum, A. martianum, A. muellerianum, and A. pseudonitidum.

Species Characters	A. atlanticum	A. martianum	A. muellerianum	A. pseudonitidum
Petiole
Surface	dull	dull	dull	lustrous
Size (cm)	11–14.4(–16)	(21.4–)24–39.6	8–10(–21)	(18.2–)27–36.4
Laminae
Shape	deltoid to lanceolate	ovate-lanceolate to triangular	lanceolate	deltoid
Division	2-pinnate	2-pinnate to 3-pinnate	1-pinnate to 2-pinnate	2-pinnate
Margin	dentate	serrate-dentate to crenate or dentate	serrate to dentate	crenate to entire
Size (cm)	14–18(–21) × 4–5(–8)	26.7–43.6 × (6.5–)10.7– 14.7(–17.4)	25–32(–44) × 5–6.5(–12)	(18.5–)25–30.5 × 9–17.2
Pinnae
Shape	lanceolate	deltoid-lanceolate to lanceolate or oblong	deltoid to lanceolate	lanceolate
Size (cm)	3–4(–6.9) × 1–1.5	(4.8–)6–9.9 × (1–)1.3–2	2.3–5.2(–7.3) × 0.7–1.1	7–10 × 1.5–3
Apex	obtuse to acute	attenuate to attenuate- caudate or acute	attenuate to attenuate- caudate	acute
Pinnules
Shape	ovate	lanceolate to deltoid or oblong	ovate-orbiculate to oblong	oblong to lanceolate
Apex	obtuse	acute to obtuse	obtuse	obtuse to acute
Stem scales
Shape	linear-lanceolate and lanceolate	lanceolate	linear-lanceolate	lanceolate
Length (cm)	0.2–0.4(–0.5)	0.2–0.3	0.2–0.3	0.2–0.3(–0.5)
Base width (cm)	(0.02–)0.03–0.05(–0.06)	0.04–0.06	–	0.04–0.07
Sori
Shape	elliptic and linear	linear	linear	elliptic