Friday, October 13, 2017

[Botany • 2017] Etlingera hamiguitanensis • A New Ginger Species (Zingiberaceae; Alpinieae) from Davao Oriental, Philippines


Etlingera hamiguitanensis  Naive


ABSTRACT

Etlingera hamiguitanensis Naive, belonging to family Zingiberaceae, is described and illustrated from the Philippines as a new species. Although similar to Etlingera philippinensis, the new species is clearly distinguished by having a shorter and heart-shaped labellum. It is also allied to E. penicillata, however, the new species clearly distinguished by having red sterile bracts.

KEY WORDS: Alpinioideae, Etlingera, Mindanao, Mount Hamiguitan, New species, Philippines.



Etlingera hamiguitanensis Naive, sp. nov.

Diagnosis: Etlingera hamiguitanensis is most similar to Etlingera philippinensis (Ridl.) R.M. Smith, but differs in the shape of the leaf (narrowly elliptic to narrowly obovate vs. broadly lanceolate), ligule (entire oblong, hyaline, reddish transluscent vs. entire triangular–oblong, papery, green) and in pubescent leaves abaxially (vs. glabrous). It also differs by having a shorter and bilobed labellum (vs. longer and entire) and by its 2–3 m tall leafy shoots (vs. 6–7 cm tall). It is also allied to Etlingera penicillata (K.Schum) A.D. Poulsen, but differs significantly in having a pubescent leaf abaxially, a much smaller leaf (30–46 × 5–9 cm vs. 67–74 × 12–14 cm), reddish, ovate to obovate sterile bracts (vs. spatulate, cream), hyaline, reddish, notched ligule (vs. entire, green ligule), inflorescence with larger, one to four flowers (vs. inflorescence with smaller, single flower) and a longer labellum (5.5–5.7 cm long vs. 3.6 to 4.2 cm long).

Fig. 2. Flower of Etlingera hamiguitanensis.
Fig. 3. Dissected flower of Etlingera hamiguitanensis. A. Sterile bracts, Fertile bracts. B. Bracteole. C. Calyx. D. Dorsal corolla lobe. E. Lateral corolla lobes. F. Stigma, Style, Epigynous gland. G. Anther, Filament. H. Labellum.
Photo by Krystal Mae Acero

Distribution: La Union, San Isidro, Davao Oriental. So far, only observed and documented from southern Philippines on Mount Hamiguitan Range Wildlife Sanctuary.

Ecology: Etlingera hamiguitanensis grows as a terrestrial herb on slopes, in shady localities with closed canopy in the buffer zone of Mount Hamiguitan Range Wildlife Sanctuary at elevations of approximately 400– 600 m above sea level. The locality was known for its unique flora because of its ultramafic soil and the species was found in an area which are dominated by different fern species and is near the stream with humid environment.

Etymology: This new species was named after Mount Hamiguitan Range Wildlife Sanctuary, where the collection was made.


Mark Arcebal K. Naive. 2017. Etlingera hamiguitanensis (Zingiberaceae; Alpinieae), A New Ginger Species from Davao Oriental, Philippines. Taiwania. 62(4); 340-344. DOI:  10.6165/tai.2017.62.340