Alsophila commutata Mett., 1863

Coritico, F. P., Amoroso, V. B. & Lehnert, M., 2017, New records, names and combinations of scaly tree ferns (Cyatheaceae) in eastern Malesia, Blumea 62 (2), pp. 92-96 : 93-95

publication ID

https://doi.org/10.3767/blumea.2017.62.02.03

persistent identifier

https://treatment.plazi.org/id/0958D47B-FFF8-FFD8-FCBC-0EA4D376F8FB

treatment provided by

Felipe

scientific name

Alsophila commutata Mett.
status

 

Alsophila commutata Mett. View in CoL — Fig. 1 View Fig ; Map 1 View Map 1

Alsophila commutata Mett.(1863) 53. — Cyathea recommutata Copel.(1909) 36, nom. nov. for Alsophila commutata Mett. , not Cyathea commutata Spreng. (1804) 146, t. 3, f. 32. — Gymnosphaera recommutata (Copel.) Copel. (1947) 98, nom. superfl. — Type: Cuming 396 (lecto K, first step, selected by Holttum (1963) 118,second step (K000636428),selected here; isolecto BM 3 sheets (BM001048020, BM001048021, BM001048022), K 2 sheets (K00636429, K000636430 p.p.), P (P00631684)), Malaysia, Malacca, 1841.

Alsophila heteromorpha Alderw.(1914) View in CoL 1; (1917) 56; (1920) 129. — Cyathea heteromorpha (Alderw.) Domin (1929) View in CoL 262. — Type: Matthew 688 (K ( K000698822 , K000698823 , K000698824 )), Indonesia, Sumatra, Gunong Sago , 29 Jan. 1913.

Alsophila heteromorpha var. decomposita Alderw. (1920) View in CoL 129. — Type: Bünnemeijer 3047 (holo L ( L0051387 );iso K ( K000698827 ),L ( L0051386 )), Indonesia, Sumatra, Mangani, Sumatra Bi Tinggi bij Mangani, 1100 m, 15 June 1918.

Cyathea hewittii Copel. (1911) 134. — Alsophila hewittii Alderw. (1917) 55; C.Chr. (in Christensen & Holttum 1934) 221. — Type: Brooks & Hewitt 21 (holo MICH ( MICH1190233 About MICH )), Malaysia, Sarawak, Bongo Mountain .

Cyathea toppingii Copel. (1917) 51; C.Chr. (in Christensen & Holttum 1934) 220. — Type: Topping 1824 (holo PNH destroyed; iso GH-00020915, NY-00127883, S (S-P-3433), MO ( MO255790 ), US ( US 00134805), MICH ( MICH1190283 About MICH )), Malaysia, Gurulau Spur, Mount Kinabalu, 21 Nov. 1915 .

Alsophila subulata Alderw. (1918) View in CoL 1. — Cyathea subulata (Alderw.) Domin (1930) View in CoL 164. — Type: Brooks 300.S (holo not located; iso BM 4 sheets ( BM001048023 , BM001048024 , BM001048025 , BM001048026 )), Indonesia, Sumatra, Lebong Simpang, Benkoelen , Aug. 1917.

Gymnosphaera squamulata View in CoL auct.non Blume (1828) 243, J.Sm. (1841) 419. — Alsophila squamulata View in CoL auct. non (Blume) Hook.(1844) 51,Hook.& Baker (1867) 235.

Tree fern. Trunks erect to decumbent, to 3 m tall, 10–16 cm diam, smooth to muricate, with old petiole bases; frond scars not observed, trunk apices not visible, covered with crowded petioles; adventitious buds present, sprouting up to 8 branches. Fronds to 210 cm long, ascending, crown funnel shaped. Petioles covered with reddish brown scales from stipe up to rachis and costa 4–6 cm long, smooth, dark purple to black abaxially and adaxially, on each side with a line of discontinu- ous small narrowly elliptic dark brown pneumatodes; coarsely dissected aphlebiae at base of petiole 4–10 pairs, reflexed to 5 cm long, evanescent with age, the strong costae remaining as blunt spines, aphlebiae either separated by gap from rest of the normal pinnae (Sumatra to Borneo) or transient with them (Sumatra, Philippines). Petiole scales marginate with one apical setae (often broken off), concordantly bicolorous, lanceolate to ovate, 8.0–10.0 by 1.5–2.0 mm, tips weakly heli- cally twisted, dark brown scale body and margins usually light brown to whitish, not orange or rufescent; petiole scurf red to reddish brown. Laminae to 210 by 75 cm, bipinnate-pinnatifid to tripinnate (when fertile), weakly dimorphic, fertile pinnules slightly contracted, subcoriaceous, ovate to elliptic, basal pinnae gradually reduced, dark green adaxially, pale green abaxially. Pinnae with stalks to 0.5 cm long, alternate, largest ones 35–40 by 14–16 cm, 11–13 pairs, costae dark brown to black on both sides. Pinnules stalked 1.0–4.0 mm long, linear oblong to lanceolate, alternate, largest ones 6.0–7.5 by 1.3–1.5 cm, cordate to weakly truncate at bases, acute at tips, alternate, 0.7–0.9 mm between the costules. Segments adnate or in lower part free tertiary leaflets, 6.0–7.0 by 2.5–3.0 mm, oblique to straight with strongly crenate margins, the sinuses somewhat triangular, 1.0– 1.5 mm between midveins, sterile segments flat, fertile segments not concave abaxially. Veins free, forked, pale adaxially, dark abaxially; basal basiscopic veins attached to the midveins. Sori near the costules, 4–5 pairs per segment. Indusia absent. Spores tetrahedral, trilete, with straight sides and broadly rounded corners, 35–40 µm. Hairs and scales: antrorsely curved, dark reddish brown hairs abundant adaxially on rachises, costae and costules; rachises and costae adaxially with few long, narrow pale brown scales and abaxially with persistent dark brown scales with pale margins; few pale brown bullate scales abaxially on costules and midveins.

Distribution — Malay Peninsula, Sumatra, and Borneo at 600–1500(–2000) m; on the Philippines only on Mt Kiamo and Mt Limbawon (Mindanao) in montane forests at c. 1600–1700 m.

Specimens examined. INDONESIA, Sumatra, Bukit Tinggi ,c. S0°18' E100°21', 1100 m, 15 June 1918, Bünnemeijer 3049 ( K) GoogleMaps ; Sumatra, Atjeh, Gunong Kemiri , c. N3°44' E97°29', 900–1600 m, 22 Aug. 1971, Iwatsuki et al. S.875 ( K) GoogleMaps ; Borneo, Kalimantan Timur, Gunung (Mt) Mandam , north of Tabang , c. 600 m, 15 Jan. 1979, Iwatsuki et al. B­2507 ( K) ; Borneo, Kalimantan Timur, Gunung (Mt) Buduk Rian , south of Long Bawan , Krayan , N03°50' E115°42', 1500–1900 m, 18 Aug. 1981, Kato et al. B­11427 ( K) GoogleMaps ; East Borneo, Mt Palimasan near Tabang on Belajan River , 800 m, 12 Sept. 1956, Kostermans 12973 ( K) . – MALAYSIA, Borneo, Sabah, Mt Kinabalu, Mesilau River , 11 Feb. 1964, Chew & Corner RSNB4331 ( K) ; Sarawak, Mount Dulit , c. N3°22' E114°12', 1230 m, 9 Sept. 1932, Richards 1638 ( K) GoogleMaps . – PHILIPPINES, Mindanao, Bukidnon, Kibalabag, Malaybalay , Mt Kiamo , along the trail going to the peak 1, N08°15.30' E125°09.321', 1634 m, 14 June 2014, Coritico FPC 133 (CMUH-00008408) GoogleMaps ; Mindanao, Bukidnon, Kibalabag, Malaybalay , Pantaron Range , Mt Limbawon ,along the trail going to the peak, N08°16.264' E125°10.853', 1698 m, 1 July 2015, Coritico FPC 232 (CMUH-00008580) GoogleMaps .

Notes — In their descriptions of A. commutata , neither Copeland (1909) nor Holttum (1963) did mention the branching of the trunks, although it is the most obvious diagnostic feature of the species in the field. At first, we mistook the Philippine plants for A. atropurpurea (Copel.) C.Chr. , due to the lack of indusia and the presence of skeletonized basal pinnae, so-called aphlebiae. This character combination defines many species of the Gymnosphaera clade ( Korall & Pryer 2014) morphologically, and A. atropurpurea was the only member of this clade hitherto known from the Philippines ( Holttum 1963). This is a low number compared to neighbouring islands ( Holttum 1963) and the presence of further species was expected when we started our study. One of the expected species was the Bornean Alsophila ramispina Hook. , a tree fern described by Copeland (1909) as bearing 3–5 branched black spines to 4 cm long at the petiole bases, which Holttum (1963) anatomically correctly identified as skeletonized basal pinnae “… all with laminae reduced to a narrow wing along veins and costae”. Alsophila commutata differs in having comparatively coarsely dissected basal pinnae with broader remnants of laminar tissue along the free veins. The skeletonized basal pinnae are usually remote from the next regular pinnae in A. ramispina and A. atropurpurea . Pictures from Malaysia ( Piggott 1988) show this gap between skeletonized and normal pinnae also for A. commutata but in the Philippine population, regular pinnae are gradually transient with the skeletonized basal pinnae, without any gap. The same can be found in some specimens from Sumatra (type of A. heteromorpha , K000698822). In their account of ferns from Sarawak, Borneo, Tagawa & Iwatsuki (1966) already pointed out the variability of this character in A. commutata .

Alsophila commutata is reliably distinguished from A. atropurpurea and A. ramispina by having short paraphyses not surpassing the sporangia (vs basally broad paraphyses with narrow filamentous apex surpassing the sporangia in the other two species). Among them, A. ramispina further shows the strongest tendency towards dimorphism between fertile and sterile leaves, with fertile pinnules sometimes only half as wide as sterile ones.

The information ‘Mt Ophir’ as type locality of A. commutata ( Holttum 1963) comes from the sheet K000636430, where a pinna labelled ‘Mt Ophir, Griffith’ is mounted below an apex labelled ‘396. Gymnosphaera squamulata Bl. , Malacca, Cuming’. The other sheets at K and those at BM and P have only the latter reference. Only the Cuming material should be considered as lectotype material ( Holttum 1963), and consequently the information ‘Mt Ophir’ can be ignored when referring to the type locality.

Copeland (1909) based his Cyathea recommutata on Alsophila commutata Mett. Mettenius (1863) mentioned an ‘ A. commutata ’ without indication of an author in his treatment of Alsophila squamulata , following a comparison with Alsophila glabra Hook. ; there is no earlier publication citing this name. Mettenius states that “ A. commutata (…) deviates in the hardcoriaceous lamina, covered with indument, half-round lobes, veins in lower number, paraphyses equalling the sporangia, partially with apex notably thickened” (pers. translation). Es- pecially the last character is in contrast to his description of A. squamulata , which is stated to have “numerous articulate paraphyses overtopping the sporangia by a little or notably, at apex attenuate or obtuse” (pers. translation). This is still a distinguishing character between the two taxa, additional to the scale type and the dimorphism in the lamina (non-marginate scales, monomorphic lamina in A. squamulata vs marginate scales, dimorphic lamina in A. commutata ). Today, A. squamulata is treated as Sphaeropteris squamulata (Blume) R.M. Tryon ( Tryon 1970, PPG 1 2016), and A. glabra and A. commutata belong to the Gymnosphaera -clade of Alsophila ( Korall & Pryer 2014) .

The placement of the description of A. commutata in the original publication ( Mettenius 1863) as a short paragraph under A. squamulata , without extra caption and printed in a smaller font makes us doubt that the author intended to describe a new species there. However, since Mettenius (1863) referred to publications of other authors who previously treated material of A. commutata as A. squamulata and summarized the differences between the two taxa, this constitutes a valid and effective publication of a new species. The collection Cuming 396 and its illustration ( Bauer & Hooker 1842) have to be re- garded as original material (Art. 9.3, Melbourne Code; McNeill et al. 2012), which Holttum (1963) correctly identified as type (first-step lectotypification), and from which we designate one sheet as lectotype (second-step lectotypification).

C

University of Copenhagen

MICH

University of Michigan

PNH

National Museum

S

Department of Botany, Swedish Museum of Natural History

MO

Missouri Botanical Garden

K

Royal Botanic Gardens

Kingdom

Plantae

Phylum

Tracheophyta

Class

Polypodiopsida

Order

Cyatheales

Family

Cyatheaceae

Genus

Alsophila

Loc

Alsophila commutata Mett.

Coritico, F. P., Amoroso, V. B. & Lehnert, M. 2017
2017
Loc

Cyathea subulata (Alderw.)

Domin 1930
1930
Loc

Cyathea heteromorpha (Alderw.)

Domin 1929
1929
Loc

Alsophila heteromorpha var. decomposita

Alderw. 1920
1920
Loc

Alsophila subulata

Alderw. 1918
1918
Loc

Alsophila heteromorpha

Alderw. 1914
1914
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