Pronephrium in Flora of China @ efloras.org

17. Pronephrium C. Presl, Epimel. Bot. 258. 1851.

新月蕨属 xin yue jue shu

Abacopteris Fée.

Plants, medium-sized, in soil. Rhizomes long creeping, or short and decumbent, with sparse usually hairy brown scales. Fronds remote or approximate; stipes glabrous except at bases, but often (particularly when young) ± with unicellular acicular hairs; laminae usually 1-imparipinnate, sometimes simple or ternate; pinnae large, usually 3-10(-15) pairs, terminal pinna free, of similar shape as lateral ones, proximal pair not or slightly shortened, lanceolate, bases rounded or cuneate, subsessile or shortly stalked, not adnate to rachises, margins entire or thickly serrate, apices acuminate; costae evident, veinlets mostly obliquely spreading; venation meniscioid, i.e., veinlets joining into oblique square areoles between veinlets, an excurrent veinlet arising from joining point of every pair of veinlets continuous or interrupted and with hydathodes at apices. Laminae herbaceous or papery, sometimes somewhat leathery, green or dark brown when dry, often reddish (at least abaxially along rachises, costae and veinlets), usually ± with acicular and hooked hairs (at least abaxially along along rachises and costae), abaxially usually foveolate on intercostal areas. Sori orbicular, in 2 lines between veinlets, one per veinlet, if attached on distal part of veinlets then usually confluent when mature, rarely spreading throughout abaxial surface of pinnae, exindusiate or indusiate, hairy or glabrous; sporangia glabrous or with acicular hairs. Spores bilateral, reniform, perispore transparent or translucent, perispore ridged corrugate, verrucate, or echinate. x = 36.

Sixty-one species: tropical and subtropical regions of Asia; 18 species (eight endemic) in China.

The following taxon is excluded from the present treatment, pending further research: Pronephrium fengkaiensis B. S. Wang & S. H. Shi (Acta Sci. Nat. Univ. Sunyatseni 29: 72. 1990).

1 Plants with hooked hairs throughout (2)

+ Plants without hooked hairs on every part (8)

2 (1) Laminae simple, strongly dimorphic, sterile laminae cordate or hastate (i.e., occasionally with one pair of small auricles proximally), sori spreading throughout abaxially on mature laminae. 1 P. simplex

+ Laminae ternate or pinnate (occasionally simple, proximally rounded or cuneate), monomorphic, sometimes dimorphic, sori arranged in lines when mature (3)

3 (2) Laminae ternate (sometimes with 2 pairs of lateral pinnae), green when dry. 2 P. triphyllum

+ Laminae pinnate and with multiple pairs of lateral pinnae, green or reddish when dry (4)

4 (3) Rhizomes short and decumbent; fronds approximate, pinnae distally usually with axillary buds in their axils. 3 P. cuspidatum

+ Rhizomes long creeping; fronds remote, pinnae distally lacking buds in their axils (5)

5 (4) Proximal pinnae obviously reduced; pinna apices abruptly narrowed into a long tail 2-4 cm. 4 P. megacuspe

+ Proximal pinnae usually largest; pinna apices not narrowed or caudate (6)

6 (5) Apical pinnae lobed throughout. 5 P. insularis

+ Apical pinnae entire (at most crenate along margins) (7)

7 (6) Laminae oblong to ovate-rounded, lateral pinnae smaller than ca. 9 ?2 cm. 6 P. longipetiolatum

+ Laminae triangular, lateral pinnae ca. 15 ?3 cm, proximal pair of pinnae largest. 7 P. parishii

8 (1) Sori exindusiate or with very small indusia (9)

+ Sori obviously indusiate (12)

9 (8) Laminae normally greenish when dry; pinnae linear-lanceolate, margins regularly and sharply serrate, pinna lobes triangular. 8 P. penangianum

+ Laminae ?purplish red when dry; pinnae ovate-lanceolate, margins entire or slightly undulate (10)

10 (9) Pinnae narrowly ovate, broadest at bases and rounded-cuneate; laminae completely glabrous on both surfaces; sori ovate and confluent when mature; Xizang. 9 P. medogensis

+ Pinnae lanceolate, broadest at middle, costae and veins with short hairs; sori orbicular and not confluent when mature; throughout China (11)

11 (10) Laminae abaxially with only sparse short hairs along rachises and costae, elsewhere glabrous; sori with small indusia. 10 P. lakhimpurense

+ Laminae abaxially with acicular hairs along rachises, costae, veins, and intercostal areas; sori exindusiate. 11 P. hirsutum

12 (8) Pinnae broadly linear-lanceolate, bases not or slightly narrowed, margins regularly serrate (13)

+ Pinnae ovate-lanceolate or falcate, bases cuneate, margins entire or irregularly undulate-crenate (15)

13 (12) Sporangia glabrous; indusia occasionally with one or two short hairs. 12 P. nudatum

+ Sporangia and indusia all with hairs (14)

14 (13) Stipes throughout with acicular setae, laminae abaxially with dense acicular long hairs along costae, veins, and on intercostal areas. 13 P. setosum

+ Stipes glabrous, laminae abaxially with only sparse hairs along costae and veins. 14 P. yunguiensis

15 (12) Rhizomes short and decumbent; plants smaller; lateral pinnae 2 or 3 pairs, pinnae ca. 7 ?2-2.5 cm. 15 P. gracilis

+ Rhizomes long creeping; plants much larger; lateral pinnae more than 4 pairs, more than ca. 15 ?3 cm (16)

16 (15) Laminae abaxially with sparse short hairs along costae and veins. 16 P. gymnopteridifrons

+ Laminae abaxially with dense long hairs along costae, veins, and intercostal areas (17)

17 (16) Pinnae ovate-lanceolate, bases rounded-cuneate; laminae not foveolate on intercostal areas, with unicellular acicular hairs; sori attached on middle of veinlets, not confluent when mature. 17 P. macrophyllum

+ Pinnae oblong-lanceolate, bases cuneate; laminae obviously foveolate abaxially on intercostal areas, with dense multicellular articulate long hairs; sori attached on distal part of veinlets and confluent when mature. 18 P. hekouensis

List of lower taxa