Luzula plumosa var. brevipes (Franch. & Sav.) Ebinger
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Authority
Ebinger, John E. 1964. Taxonomy of the Subgenus Pterodes, Genus Luzula. Mem. New York Bot. Gard. 10 (5): 279-304.
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Family
Juncaceae
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Scientific Name
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Discussion
Luzula rufescens Fisch. ex E. Mey. var. brevipes Franchet & Savatier, Enum. PI. Jap. 96. 1879.
Luzula japonica Buchenau, Bot. Jahr. 12: 82. 1890.
Juncodes japonicum (Buchenau) 0. Ktze. Eev. Gen. PI. 2: 724. 1891.
Luzula macrocarpa (Buchenau) Nakai var. laxa Nakai, Eep. Veg. Quelpqert 30. 1914.
Luzula plumosa Wall, ex E. Mey. var. bracTiycarpa Satake, Jour. Fac. Sci. Tokyo Bot. 4: 194. 1933.
Luzula brachycarpa (Satake) Satake in Nakai & Hondo, Nova Fl. Jap. 24. 1938.
Luzula jimboi Miyabe & Kudo var. integra Satake in Nakai & Hondo, Nova Fl. Jap. 17. 1938.
Luzula plumosa Wall, ex E. Mey. var. sphaerosperma Satake, Jour. Fac. Sci. Tokyo Bot. 4: 195. 1933.
Luzula formosana Ohwi, Acta Phytotax. Geobot. 1: 79. 1932.
This variety can be distinguished from others of Luzula plumosa by its capsule which is longer than the perianth, and its erect to slightly curved caruncle that is shorter than the seed. In the other two varieties, in contrast, the capsule equals to slightly exceeds the perianth and the caruncle is usually strongly hooked, and equals the seed in length. Moreover, variety brevipes may be distinguished from variety refle.ra by its narrower leaves, and from variety plumosa by its spreading to reflexed pedicels. This variety is generally restricted to the islands of Japan, but is occasionally found in Korea (Fig. 7).
Type. Savatier 3368; collected in the mountainous province of Senano (now called Nagano), Saba, Japan, (not seen.)
Hybrids. No naturally occurring hybrids have been reported, and none were found during this study. The only taxon that it is possible for variety brevipes to hybridize with is Luzula rostrata. Hybrids were not found, however, which is probably the result of the difference in flowering time of the two taxa. It is also possible that an ecological barrier exists, but this could not be determined with certainty. From the data that was present on the herbarium sheets it was determined that variety brevipes blooms during April and May, while L. rostrata blooms in June and July. Also, L. rostrata is restricted to mountainous regions while variety brevipes grows at low altitudes. There were, however, a few specimens of this variety that bloomed later in the season while other specimens were found growing at fairly high altitudes. Thus the opportunity for hybridization may sometimes occur.
Morphologically this species is intermediate between the European species and the Asiatic species Luzula rostrata. L. plumosa var. plumosa is similar to L. forsteri in that the pedicels are erect, the flowers are essentially the same size, and the capsules equal to slightly exceed the perianth. It can be separated readily from this European species, however, since the leaves are wider, there is no mueronate projection extending from the callose tip of the leaf, and the caruncle is much larger. In contrast, var. reflexa is morphologically very close to L. pilosa. It can be separated from this species by the wider and longer culm leaves, the slightly longer perianth and the anther length which equals to slightly exceeds the filaments. Variety brevipes, in contrast, is more similar to L. rostrata than the European species. However, it can be distinguished from L. rostrata by its narrower culm leaves that do not taper abruptly to the callose tip, the longer perianth segments and the strongly compound inflorescence with spreading to reflexed pedicels.
The nomenclature of Luzula plumosa var. plumosa is very simple, and only three synonyms are listed. Two of these represent transfers of the specific epithet plumosa, either to varietal status or to another generic name that is now considered a synonym of the genus Luzula. The third is a herbarium name, Juncus plumosus, which was listed as a synonym of L. plumosa. Variety brevipes, in contrast, has numerous synonyms which are a result of the large amount of variation found in this variety. It has been generally considered to be allied to L. plumosa, and in the most recent flora of Japan is referred to as L. plumosa var. macrocarpa (Buchenau) Ohwi (1953). This variety name was taken from L. rufescens var. macrocarpa Buchenau. The type of this name was examined and it is referred to L. rufescens. Therefore the varietal name macrocarpa cannot be used for this Japanese material. Oddly enough Ohwi lists L. rufescens var. brevipes as a synonym of L. plumosa var. macrocarpa. This is a much earlier name than macrocarpa, and according to the rule of priority should have been used for this taxon. In this study the name brevipes is transferred to L. plumosa and refers to this Japanese material. Numerous other names (varieties and species) have been used also to refer to this material. These names are a result of the large amount of variability found in the same specimen or throughout a single collection and does not show geographic or ecological differences.
Very few specimens of this species were available for study; therefore it was impossible to determine the total range of variability. However, the recognition of the varieties reflcca and brevipes seems justified. Their different geographic ranges indicate that they are distinct, as do their different morphological characteristics. However, it m a y be more realistic to treat this complex as two or more species if future evidence, based on cytology and breeding experiments, suggest it.