• Korean Journal of Plant Taxonomy
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• v.45 no.1
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• pp.12-16
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• 2015

Draba ussuriensis Pohle is reported from Mt. Baekdu in this paper as a new member of Korean flora. D. ussuriensis is a white-flowered perennial herb and similar to Draba mongolica Turczaninow. However, D. ussuriensis differs from Draba mongolica Turczaninow in a number of characters. The stems and pedicels of D. mongolica are covered by dense trichomes, while those of D. ussuriensis are glabrous or glabrescent. D. ussuriensis has fewer cauline leaves compared to D. mongolica. The Korean name of D. ussuriensis Pohle stems from the specific epithet of its scientific name. In addition, D. mongolica is a new name, replacing the previously misidentified names of D. glabella Pursh, D. daurica DC., D. incana L., and D. nipponica Makino in several different studies. We corrected the name based on a comparative morphological study of specimens collected from Mt. Baekdu and Gwanmobong and related species. As a result, Korean Draba consists of three species: two white-flowered species and one yellow-flowered D. nemorosa L.

• Korean Journal of Plant Resources
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• v.25 no.2
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• pp.257-270
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• 2012

The taxonomic relationship of 3 taxa in $Carex$ sect. $Siderostictae$ were revealed by morphological and molecular studies. The morphological characteristics of Korean $Carex$ siderosticta Hance, which is a type species of sect. $Siderostictae$, was first reviewed in comparison with previous records in order to identify the difference. Then the distribution map of this species was formulated through previous floral literatures and voucher specimens. Although the leaf shape which is represented by length/width ratio showed a great variation depending on habitat condition, the rhizome creeping patterns, the presence of hair on the surface leaf margin and perigynium were shown to be good diagnostic characters to define delimitation of species level. The results from molecular study supported $C.$ $ciliatomarginata$ Nakai should be ranked independently on species level.

• Korean Journal of Plant Taxonomy
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• v.35 no.4
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• pp.227-245
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• 2005

Numerical analysis using morphological characters was done in order to clarify taxonomic circumscriptions and identities of Korean endemic, Cirsium setidens (Dunn) Nakai, Cirsium chanroenicum Nakai, and Cirsium toraiense Nakai ex Kitam.. Principal components analysis of C. setidens and C. chanroenicum using 29 morphological characters and 12 leaves characters revealed one group which could not separate. Identity of C. toraiense could not be confirmed by the destruction of habitat, similarity of morphological diagnostic characters between many specimens identified C. toraiense including type specimen and C. japonicum var. ussuriense. In considering the variational patterns of morphological characters, it is strongly suggested that identities of C. setidens f. alba, C. setidens var. niveo-araneum, and C setidens var. pinnatifolium should be recognized, but C. chanroenicum var. lanceolata should be included to circumscription of C. setidens.

• Korean Journal of Plant Taxonomy
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• v.36 no.2
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• pp.109-127
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• 2006

A taxonomic study of Habenaria in Korea was carried out based on the extensive examinations of floral morphologies and distribution. As the results, we classified the genus in Korea into the following 5 species; H. linearifolia Maxim., H. cruciformis Ohwi, H. radiata Splengl., H. chejuensis Y.N. Lee & K.S. Lee and H. flagellifera Makino. H. cruciformis is recognized as a distinct species distinguished from H. linearifolia, H. sagittifera Rchb. f. and H. schindleri Schltr., and we clarified its morphological differences from the species. H. linearifolia f. integrilova Ohwi which has been seperated by shape of lateral lobe of lip was merged into f. linearifolia oin this study. Furthermore we investigated the distribution of Habenaria in Korea based on the herbarium specimens and field surveys. The result shows that H. radiata is rare in the middle part of the Korean Peninsula and H. chejuensis and H. flagellifera are restricted in Jeju Island, so the conservation on the habitats of these species is required.

• Korean Journal of Plant Taxonomy
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• v.44 no.2
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• pp.77-80
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• 2014

Here we report a previously unrecorded species of Korean Myriophyllum L. (Haloragaceae). This taxon, M. oguraense Miki has been regarded as a Japanese endemic for some 60 years. Myriophyllum oguraense and its closely related M. verticillatum L. share the characteristic of having pectinate emergent leaves that are similar in shape to, but much smaller than, the submerged leaves. However, the primary characteristic that differentiates these taxa is the turion shape (club shaped in M. verticillatum and linear in M. oguraense). The common name, 'Gin-dong-a-mul-su-sae-mi' was also newly given considering its characteristic turion shape. Photographs and a key to Korean Myriophyllum species are provided in addition to complete descriptions including information on nomenclatural types, distributions and specimens examined.

• Journal of the Korea Institute of Building Construction
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• v.16 no.4
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• pp.305-311
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• 2016

This study examined the long-term inelastic characteristics, including unrestrained shrinkage and creep, of low-heat cement concrete under different ambient curing temperatures. To achieve the designed compressive strength of 42MPa, water-to-binder ratios were selected to be 27.5, 30, and 32.5% for curing temperatures of 5, 20, and $40^{\circ}C$, respectively. Test results showed that the shrinkage strains of concrete mixtures tended to decrease with the decrease in curing temperature because of the delayed evaporation of internal capillary and gel waters. Meanwhile, creep strains were higher in concrete specimens under lower curing temperature due to the occurrence of the transition temperature creep. The design models of KCI provision gave better accuracy in comparison with test results than those of ACI 209, although a correction factor for low-heat cement needs to be established in the KCI provision.

• Korean Journal of Plant Taxonomy
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• v.45 no.2
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• pp.114-135
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• 2015

The taxa of Dryopteris subg. Erythrovariae are variable in morphology, resulting in taxonomic confusion in delimiting taxon boundaries. We examined the morphological characteristics of the Korean members of subg. Erythrovariae to clarify their taxonomic identities and relationships. The shapes of the blades, pinnae, and pinnule apices, the shapes and colors of the scales, and the positions of sori were useful for delimiting the Korean taxa of the subgenus. Based on the results of this study and evidence from previous studies, 13 taxa comprising 12 species and one variety of Dryopteris subg. Erythrovariae were recognized in Korea. Descriptions of all Korean taxa of the subg. Erythrovariae and a key to the species are provided. The descriptions presented here are based on field observations and the examination of some 1,000 specimens from the major herbaria of the world.

• Korean Journal of Plant Taxonomy
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• v.45 no.2
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• pp.178-182
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• 2015

Stellaria sessiliflora Y. Yabe (Caryophyllaceae), which is known to be distributed throughout Japan excluding Okinawa, was recently found on Jeju Island in Korea. Reports on the Japanese flora state that this species is distributed on Jeju Island, and a photograph of one specimen (Slide No. 6294) collected from Jeju Island by Ohwi in May 1935 confirms this. Additionally, specimens at the National Arboretum and Korea Forest Research Institute indicate that S. sessiliflora has occurred on Jeju Island for a considerable amount of time. However, the species has never been officially listed in the flora of Korea. Stellaria sessiliflora is distinguished from S. media by having broader leaves with a slightly undulate margin, petiolate leaves on the upper part of the stem, and 10 stamens. The local name 'Geu-Neul-Byeol-Kkot' is given to the species based on its shady habitat under deciduous broadleaf forest. Details of the morphological characters, an illustration, the type specimen, voucher specimen data, and photographs of Stellaria sessiliflora in Korea are presented.

• Journal of the Korea Institute of Building Construction
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• v.17 no.3
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• pp.269-277
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• 2017

In this work, as a preliminary experimental works, which focuses on utilizing separated pastes from activated (or radioactive) concrete as solidifying agents for radioactive waste immobilization, were performed. It was found that density of hydrated cement paste, which was lower than that of ordinary portland cement, increased as temperature for heat treatment increased. Highest compressive strength was observed with the specimens that was heat treated at $600^{\circ}C$. However, heat treatment over $700^{\circ}C$ showed higher CaO content that caused higher heat of hydration after in contact with water, lows of workability, and lower strength. Based on experimental results, it is suggested that $600^{\circ}C$ heat treatment is more appropriate for waste cement paste to be used as a solidifying agent.

• Korean Journal of Plant Taxonomy
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• v.34 no.4
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• pp.287-295
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• 2004

Daucus species vegetated in the island Dae-heug-san-do off the Korean Peninsula has been recorded as Daucus littoralis Sibth. et Sm. var. koreana Nakai, endemic to Korea in several flora. However, the name was revealed as a naked name, nomen nudum, because the valid publication and type specimens were found anywhere. Comparative observation on morphological characters between the Korean taxon of Daucus and D. littoralis reveals that the Korean vegetated in the island Dae-heug-san-do is not the D. littoralis, but the D. carota L. subsp. carota. The Korean name of the latter is designated newly as San-dang-geun. The new korean name, Seon-dang-geun, of the unrecorded taxon, D. carota subsp. maritimus (Lam.) Batt., is also given.