ACROSTICHACEAE [Draft]

卤蕨科 lu jue ke

Dong Shiyong ([Chinese]); A. Michele Funston

Ferns, terrestrial, of wet places. Rhizome creeping, ascending, or erect, stout, scaly. Fronds dimorphic, or monomorphic but distal pinnae fertile only. Lamina 1-pinnate, firmly herbaceous, papery, or leathery, both surfaces glabrous; sterile pinnae lanceolate or tongue-shaped to narrowly oblong, margin entire, apex obtuse or acuminate; fertile pinnae ± contracted, linear to narrowly lanceolate. Veins anastomosing, visible on both surfaces, without included veinlets. Sori acrostichoid, sporangia covering abaxial surface of pinnae except on costae and/or very near costae and margin; sori exindusiate, or somewhat covered by reflexed pinna margin, numerous trichomes presenting in sori.

Two genera and four species: pantropical distribution; one genus and two species in China.

1. ACROSTICHUM Linnaeus, Sp. Pl. 2: 1067. 1753.

卤蕨属 lu jue shu

Plants terrestrial or in coastal swampy places. Rhizome creeping or erect, dictyostelic with additional strands; scales large, broadly lanceolate or ovate-lanceolate, entire. Fronds clustered or approximate, stipe stout, glabrous; lamina 1-pinnate with distinct terminal pinnae; pinnae stalked, tongue-shaped to narrowly oblong, papery to thickly leathery or fleshy, entire, apex obtuse to acuminate; veins anastomosing, without included free veinlets. Fertile pinnae borne in apical part of lamina or on most or all of fertile lamina, slightly contracted, evenly covered by sporangia. Spores tetrahedral-globose, perispores papillate to tuberculate, with rodlets or sparse strands. x = 30.

Three species: pantropical; two species in China.

1a.     Sterile pinnae rounded, truncate, or retuse and shortly mucronate at apex ............  1. A. aureum

1b.     Sterile pinnae narrowly acuminate at apex ....................................................  2. A. speciosum

1. Acrostichum aureum Linnaeus, Sp. Pl. 2: 1069. 1753

卤蕨  lu jue

[??synonyms]

Plants 1–2 m tall. Scales on rhizome dark brown to black, broadly lanceolate, 1–2 × 0.2–0.6 cm. Stipe stramineous to pale castaneous, 10–70 cm, 0.5–1 cm in diam., glabrous upward; lamina 40–50 × 20–40 cm, imparipinnate, thickly leathery, both surfaces glabrous; lateral pinnae to 5–12 pairs; pinnae narrowly oblong, (10–)15–35 × 1.8–5.5 cm, with stalk 0.5–1.5 cm, base cuneate to rounded, margin entire and cartilaginous, apex rounded to retuse and shortly mucronate; costae strongly raised abaxially, flat or slightly grooved adaxially; veins raised abaxially, hardly visible adaxially, close, anastomosing. Fertile pinnae only on upper portion, like sterile ones but slightly smaller. Sporangia scattered throughout abaxial surface; paraphyses capitate, with lobed apical cells.

Coastal swamps, usually in mangrove swamps; near sea level up to 100 m. Guangdong, Guangxi, Hainan, Taiwan, Yunnan [Cambodia, Japan (Ryukyu Islands), Malaysia, Thailand, Vietnam; tropical regions of Africa, America, Asia].

2. Acrostichum speciosum Willdenow., Sp. Pl., ed. 4, 5: 117. 1810.

尖叶卤蕨  jian ye lu jue

Plants 1–1.5 m tall. Scales on rhizome dark brown to black, broadly lanceolate, ca. 1 × 0.2–0.3 cm. Stipe stramineous, 30–40 cm, 0.3–0.5 cm in diam., glabrous; lamina 35–50 × 20–30 cm, thickly leathery, both surfaces glabrous, imparipinnate; lateral pinnae to 5–8 pairs; pinnae lanceolate, (8–)15–20 × 2–2.5 cm, with stalk 0.5–1 cm, base narrowly cuneate, margin entire and cartilaginous, apex narrowly acuminate; costae strongly raised abaxially, flat or slightly grooved adaxially; veins raised abaxially, hardly visible adaxially, close, anastomosing. Fertile pinnae only on upper portion, like sterile ones but somewhat abruptly attenuate and shortly caudate. Sporangia scattered throughout abaxial surface; paraphyses capitate, with lobed apical cells.

Mangrove swamps; near sea level. Hainan (Wenchang) [Malaysia, Thailand, Vietnam; tropical Asia, Australia].