Spicantopsis niponica (Kunze) Nakai var. minima Tagawa (1938: 706)

Molino, Sonia, Santos, Guillermo, Vázquez, Rubén, Medina, Rafael & Gabriel, José María, 2024, Monograph of the genera Struthiopteris Scop. and Spicantopsis Nakai (Blechnaceae, Polypodiopsida), Phytotaxa 677 (1), pp. 1-48 : 20

Spicantopsis niponica (Kunze) Nakai var. minima Tagawa (1938: 706) ( Figure 13B‒C ).

Type:— JAPAN. Kyushu , Prov. Osumi, Hananoego , Isl.Yaku-sima, 18August 1933, M. Tagawa 853 ( KYO not seen, holotype; P00748579 !, isotype; US 00135467!, isotype) .

Synonyms:—≡ Struthiopteris niponica var. minima (Tagawa) Masamune (1951: 198) .

Invalid designation: Blechnum niponicum var. minimum (Tagawa) Nakaike (2013: 23) nom. inval. (basionym ref. incorrect).

Plants terrestrial; rhizomes thick, very short, erect, with scales ovo-lanceolate, papyraceous, discoloured, centre broadly sclerotized from base to apex, dark brown, margins lighter brown, entire, 0.3‒0.7 x 3‒4 mm; fronds dimorphic, sterile fronds 4‒7 cm long, shortly petiolate, stipes no longer than 1.5 cm, laminae elliptic-lanceolate, coriaceous,1.5‒3 x 5‒10 cm, 1-pinnate or pinnatifid, with conform apex, rachis grooved adaxially, pinnae tapering towards the base, the middle ones 015‒0.3 x 0.6‒1.5 cm, veins free, simple or 1-furcated, catadromous, ending in submarginal, patent hydathodes; fertile fronds longer than the sterile ones, 6‒15 cm long, stipes 1‒2 cm, laminae elliptic-lanceolate, 1‒2 x 6‒15 cm, 1-pinnate with conform apex, pinnae contracted, the middle ones 0.1‒0.2 x 0.5‒1 cm; sori linear, continuous, forming coenosori on both sides of costa, occupying the entire length of the pinna; indusia continuous, long and coiled; sporangia and spores not seen.

Habitat and distribution:—Endemic to Japan ( Iwatsuki 1992), originally described as an endemism of the Yakushima Island ( Tagawa 1938), but we have found specimens from Kyoto prefecture (Honshu) and Yamagata prefecture (Kyushu). On road slopes and rock crevices. 60‒800 m ( Figure 7 ).

Chromosome number:—2 n = 62, diploid ( Shinohara & Murakami 2006).

Etymology:—The epithet minima refers to its small side compared to the type variety.

Vernacular names:— Hime-shishigasira (ヒメシシガシラ, Japanese) ( Iwatsuki 1992). Hime-shishigasira means something like “princess lion head head”, meaning that it is a small version of the lion head fern ( S. niponica ).

Taxonomic notes:— It can be distinguished from S. niponica var. niponica by having smaller rhizome, rhizome scales, and fronds, and simpler venation. This variety has been little studied at the anatomical and palynological level because most of the material examined was type material. For this reason, in the study of Molino et al. (2019b) it could not be included in the phylogeny, and only two sequences of two markers already deposited in GenBank were available. Therefore, a more detailed study of this variety would be interesting to determine its taxonomic status.

Additional specimens examined:— JAPAN. Honshu. Pref. Kyoto: Lom Mio , en exposition SW aux environs du K. I. C. H., 13 July 1969, H. de Leiris s.n. ( P06491206 !) . Kyushu. Pref. Kagoshima: Yakushima Island, Hananoe , Kawaichi , Kosugi valley , 4 August 1939, Y. Kimura 39169 ( TI00274342 ! photo) ; Yakushima Island, Prov. Satsuma, to Shika-no-sawa from halfway-midpart Mt. Nagata-dake , Kami-yaku-choo, 12 October 1963, M. Furuse 41658 ( TI00274303 ! photo) ; Yakushima Island, Prov. Ohsumi , 25 October 1950, S. Hatusima 14680 ( US 2138202!) ; Yakushima Island, Yakumachi, Mt. Motchom (Onoaida-peak-Tanayokehodo-Sempiro Fall ), 23 July 1982, T. Yahara et al 6201 ( TI00274380 ! photo). Pref. Yamagata: Kaminoyama-shi, N. slope of Dorobu, 23 June 1995, Y. Endo et al. 19 ( MO05088220 !) .

Figures

FIGURE 7. Distribution of Spicantopsis niponica extracted from GBIF. Purple circles: S. niponica var. niponica; yellow squares: S. niponica var. mínima (added manually).

FIGURE 13. Illustration of Spicantopsis niponica. A. Habit of S. niponica var. niponica (J. Umemura 37, P01406521); B. Rhizome scale of S. niponica var. minima (M. Tagawa 853, P00748579, isotype); C. Habit of S. niponica var. minima (M. Tagawa 853, P00748579, isotype); D. Sporangium of S. niponica var. niponica (B. Estébanez s.n., MACB110657); E. Rhizome scale of S. niponica var. niponica (Maximowicz s.n., S2145). Scale: 4 cm in A; 500 µm in B; 4 cm in C; 100 µm in D; 1.5 mm in E.