A New Species of the Athyriaceae from Hong Kong:

Diplazium taimoshanensis Ng et al., stat. nova

Ng et al., 23rd Nov., 2005

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Summary


We confirmed a new Diplazium species exists in Hong Kong, which resembles the species: Diplazium serratifolium Ching, Diplazium maonense Ching and Diplazium doniamum (Mett.) Tard.-Blot. Based on the similar morphological characterizes for those of Diplazium serratifolium Ching, we believed that there is a geographic variety firstly, but differs primarily in its creeping rhizome, then compared with Diplazium maonense Ching and Diplazium doniamum (Mett.) Tard.-Blot again. As the result, It is considered a new species in Hong Kong.


Keywords

Tai Mo Shan, Athyriaceae, Diplazium, Diplazium serratifolium Ching, Diplazium taimoshanensis Ng et al. stat. nova, Diplazium doniamum (Mett.) Tard.-Blot and  Diplazium maonense Ching.


Etymology


Specific epithet "taimoshanensis" is from Tai Mo Shan, name of the highest mountain in Hong Kong which are 958 meters in the peak, and where the new species is discovered.


Key to Genus Diplazium (incl. D. taimoshanensis, D serratifolium)
and known species Diplazium of Hong Kong

All of about 30 species of Diplazium are well known in the world (using Ching's system of classification ) and only 4 species found in Hong Kong.

1. Lamina single, tapering to either end, margin entire
                                                ........................... Diplazium subsinuatum (Wall. ex Hook. et Grev.) Tagawa
                           or pinnately    ........................... Diplazium tomitaroanum Masamune
     2. Lamina pinnate, 1 terminal pinna with pairs of lateral pinnae.
                 3. Lateral pinnae: 10cm~12cm long, by 3.5cm from voucher specimen from Hong Kong ( data from 
                    
  literature: 20cm long by  2.5~5cm max.), margins entire, subentire or undulate, crenation at apex. 
                                                      ........................... Diplazium donianum (Mett.) Tard.-Blot
                 3. Crenation at lateral pinnae from upper base to apex.
                     4. From voucher specimen from Hong Kong, lateral pinnae it measures 11cm, by 2.5 ~ 4 cm (18cm
                          long max from literature), ovate-lanceolate. "Terminal pinna: lobes in lower part
                                                     ...........................  Diplazium maonense Ching
                     4. Lateral pinnae measures 11 ~ 21 cm long, by 2.5~5cm or above, similar to terminal pinna, and with
                           falcate apex.
                         5. Rhizome erected, Stipes tufted, length of pinnae measures 11 ~ 18 cm long, by 2.2 ~ 4 cm,
                               crenation at middle and  upper part    ........................... Diplazium serrtifolium Ching
                         5. Rhizome creeping, short. Stipes spaced on the rhizome, lamma pinnate, 16~21 cm long, by 4 ~5
                                cm (or above) wide, margins almost regular serrations or toothed at the mature age. 
                                                                     ........................... Diplazium taimoshanensis Ng et al.


Classification and Botanical Morphology


PHYLUM PTERIDOPHYTA
     SUBPHYLUM: Filicophytina
          Class: Leptosporangiopsida
              Order: Polypodiales
                  Family: Athyriaceae
                         Genus: Diplazium
                                Sawtoothed Lady-fern  ( Diplazium taimoshanensis Ng et al., 2005, stat. nova. )
                                                                                      Flora Ngiana, Acta Scientrium Ngensis,  XI, 2005.

 Type Specimen Here!

Rhizome: black, short-creeping, with few scales, with a mass thick root, 5cm depth underground, hard and woody. Stipes: about 18 ~ 35cm long, spaced on the rhizome, few black scales in the base, black. about 0.1~0.3cm dia., Scales with tooth margin, less than 0.5 cm long. Lamina: texture thick papery or coriaceous, simply pinnate, 18~30cm long by 20cm wide, with 1~2 pairs of lateral pinnae and a simple terminal pinna, pinnae lanceolate, with falcate apex. Terminal pinna is slightly longer than lateral, opposite at lower pairs. attachments petiolate. Pinnae: margins undulate or serrate at the middle and lower, and almost regular serrations or toothed at the mature age. Serrate crest measures 0.05cm and 0.2 cm max. Veins: oblique and forked, free, each branch grouped with 3 (or 4) single veins. Sori, dark-yellowish, along the basal veins, elongate, at the middle between the mid-rib and margin, with elongate indusium. length differ.

Species proxime affinis Diplazium donianum (Mett.) Tard.-Blot, a qua differt statu multo majore, marginibus serraturis majoribus preaditis, pinnis paucioribus, tenuribus, utroque sensim angustatis.

Planta 75cm alta. Rhizomate repente, paleis rhizomatis nigris, ovata-lanceolatis, marginibus inciso-serratis. Stipite ad 18~35cm longo, ca. 0.1~0.3 cm diametro, basi stipitis paleis fuscis. Pagina frondis textura chartacea, lamina oblonga, 18~30cm longa, 20cm lata, pinnara cum pinna impair terminali lateralibus simili, 1-2-jugis, magnitudine similibus, utroque sensim angustatis, apice longe acuminates. Pinnis margine serratis. Venis trifurcates, Soris lineribus, plerumque diplazioideis, indusiis linearibus.

Illustrations: 1. the whole plant,    2. Rhizome with stipes,   3.Part of fertile frond,   4. Mid-lower part of a pinna,    5. scale,   (drawn refer series of typus and isotypus specimen: NSF-F36808, A, B, C)


Distribution

Tai Mo Shan, Hong Kong, locally quite rare and only few spots were found in the single point from the secondary forest, at altitude 780m circa, under the shelter from giant rocks, It is associated several species of Bambusa and other ferns such as: Vittaria flexuosa Fee, Asplenium austrochinense Ching, etc. Other rare species, the very rare orchid species to Hong Kong, Anoectochilus yungianus S.Y. Hu, also been found at the same place.


Special Note

Cognitio Sapiens Ngensis (), code name for our researching projects, both social  and natural science, we organize an expedition team for investigation into the flora of Hong Kong, it will pay to be assiduous and honest to this job. It differs greatly from others, we don't need spend more money which from the foundations, but only traffic disbursement, foods and walks. we need the truth, instead of those of  honor that carries no privilege.

Pteridology of Hong Kong is the most glamorous for us because more works still should be needed. We do believe that there are still exists of many hidden ferns species in Hong Kong. But,

How and when can we find them?

We volunteered for this hard and unprofitable job and try to do our best to solve the problem.


References


(1) Ching in Hong Kong Naturalist, 7(1): 88, 1938.
(2) Ching et Wang in Materials for the Pteridophytic Flora of Hainan, Acta Phytotax. Sin. 8 (2), 1959.
(3) Ching et Wang in Additional Materials for the Pteridophytic Flora of Hainan, Acta Phytotax. Sin. 8 (2), 1959.
(4) Editional Committee of the Flora of Taiwan, Flora of Taiwan, Vol.1, Pteridophyta. Gymnospermae, Taipei, Taiwan, ROC, 1994.
(5) Editional Committee of the Flora of China, Icongraphia Cormophytorum Sincorum, Tomus I, 1995.
(6) H. H. Edie, Ferns of Hong Kong, Hong Kong University Press, 1978
(7) Hong Kong Herb., Check List of Hong Kong Plants 2004, 2004.
(8) Kuo, Photographic guide to 300 species of Taiwan Ferns, 2003.
(9) Li Jian-zong et al., Flora of Hunan, Vol. 1, Hunan Science & Technology Press, 2004.
(10) Wu Shiew-hung et al., Flora of Hong Kong - Pteridophyta, Kadoorie & Botanic Garden, 2003.
(11) M. L. So, Hong Kong Ferns, Urban Council, HK., 1994
(12) W.M.Chu et Z.R. He, Flora of China, Vol.3 (2), Science Press, 1999.


        


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