Scaphochlamys tahanensis Y.Y. Sam & Saw, 2015

Sam, Yen Yen, Ibrahim, Halijah & Saw, Leng Guan, 2015, Four new species of Scaphochlamys (Zingiberaceae) from Peninsular Malaysia, Phytotaxa 221 (1), pp. 21-34 : 30-33

4. Scaphochlamys tahanensis Y.Y. Sam & Saw , sp. nov. ( Figs. 7–8 )

Scaphochlamys tahanensis is most similar to S. concinna but differs in having a channelled petiole compared to the terete petiole in S. concinna . Scaphochlamys tahanensis also differs in its cuneate or attenuate lamina base versus the cordate base in S. concinna .

Type: — PENINSULAR MALAYSIA. Pahang: Lipis, Taman Negara, Sungai Tanum Basin , Kuala Juram , 31 July 1996, L. G . Saw FRI 44667 (holotype: KEP!, isotypes: AAU!, K!) .

Rhizomatous herb, 30–50 cm tall, successive shoots clustering close together. Rhizome 2–3 mm diameter when dried. Bladeless sheath 2–3, largest 6.5–13 cm long, brownish purple, persistent. Leaf 1 per shoot, glabrous; sheath 2–3 cm long, thin, base slightly swollen; ligule small, less than 1 mm long; petiole plus sheath 10.5–27.5 cm long, channelled; lamina 18–31 × 3.1–4.3 cm, narrowly elliptic to lanceolate, apex attenuate, base cuneate or attenuate. Inflorescence 4.5–10 cm long, glabrous; peduncle 1.2–7 cm long; rachis 2.5–4 cm long, compact, axis not visible, composed of 4–10 red floral bracts, bracts overlapping and closely appressed to axis. Largest floral bracts 21–40 mm long, boatshaped, 9–13 mm width when flattened, glabrous, texture coriaceous, not stiff, margin incurved but not overlapping, apex narrowly acute, pointed upright. Cincinnus with 2–3 flowers in each bract. First bracteole 18–36 mm, near linear with margin inflexed and overlapped, 2-keeled, glabrous, apex narrowly acute; subsequent bracteoles reducing in size. Flowers 50–55 mm long, white, except labellum; exert 5–10 mm from floral bracts. Calyx 10–14 mm long, tubular, glabrous, unilaterally split 5–6.5 mm from apex, apex acute. Floral tube 32–38 mm long; dorsal corolla lobe 14–17 mm long, near triangular, edges inflexed, apex hooded and ending with pointed tip; lateral corolla lobes 12–16 mm, edges inflexed, apex acute. Staminodes 10–14 × 5–6 mm, oblanceolate, apex rounded, adaxial surface covered by glandular hairs. Labellum 17–22 × 15–17 mm, obovate, apex bilobed, lobes overlapped, cleft 5–9 mm from apex, abaxial surface covered with glandular hairs, yellow median band with red streaks at both sides. Stamen ca. 7 mm long, covered by glandular hairs on abaxial surface; filament ca. 2 mm long; pollen sacs ca. 4.5–5 mm long, basal spurred, dehiscing longitudinally; anther-crest ca. 1 × 2 mm, not extended and not recurved. Stigma less than 1 × 1 mm, beak-like, ostiole narrow and facing front, ciliate. Ovary 2–3 × ca. 2 mm, glabrous, unilocular, ca. 6 ovules. Epigynous glands filiform, two, 7–10 mm long.

Etymology:—The epithet refers to Gunung Tahan where the plants were found.

Distribution and habitat:—Endemic to Taman Negara, Pahang, Peninsular Malaysia. Lowland dipterocarp to upper hill forest, 30–1098 m elevation, riverbanks, in shaded areas.

Conservation status:—Rare, RA. Healthy and abundant populations are found from the foothills to hill slopes of Gunung Tahan within Taman Negara. The RA category was created under the Malayisan Plant Red List for taxa that are rare but not threatened by extinction ( Chua 2012). However, taxa that fall under this classification should be given due attention in conservation decision-making and processes.

Additional specimens examined (paratypes):—PENINSULAR MALAYSIA. Pahang: Merapoh , near base camp, 22 June 1995, H. C . Ong 633 ( KLU!); Lipis, Taman Negara, Gunung Tahan, Kem Koh , ascent from Merapoh , 650 m, 3 August 1996, R . Kiew RK 4034 ( KEP!); ascent from Merapoh HQ, 1098 m, 7 August 1996, R . Kiew RK 4120 ( KEP!); Kuala Juram, Sungai Tanum , 30 m, 5 May 1997, L. S. L . Chua FRI 38849 ( KEP!); Camp Kor, Kor Camp site, 479 m, 6 May 2008, K . Imin FRI 63068 ( KEP!, SAN!, SING!) .

Discussion:— Scaphochlamys tahanensis is close to S. concinna Holttum (1950: 94) with both having long, narrow leaves and red, short and compact inflorescences. In addition, both also have conspicuously large white flowers with red streaks beside the yellow median band on the labellum. Nevertheless, S. tahanensis is easily distinguished by its very narrow lamina with the ratio length to width of 5.6–9.8. The similar looking S. concinna has lower ratio of 2.6–4.3 and its shape is narrowly lanceolate to ovate with strongly cordate base whereas S. tahanensis is narrowly elliptic to lanceolate with cuneate or attenuate base. Other differences are observed in the inflorescence structure. For example, the inflorescence rachis of S. tahanensis is 2.5–4 cm long and it consists of 4–10 floral bracts whereas S. concinna has longer rachis (4–4.5 cm) because it consists of more bracts (about 14 bracts). The difference in the cross section of petiole in S. tahanensis and S. concinna further supports their specific status. The petiole in cross section is characteristic to each species and all the Scaphochlamys species observed so far fall nicely into either one of these two groups (channelled versus terete petiole).

Scaphochlamys tahanensis and S. concinna are not sympatric because they occupy different locations. Scaphochlamys tahanensis is found along the trail at the western entry point to Gunung Tahan, the highest peak in Peninsular Malaysia. Gunung Tahan is located in the Tahan Range, a mountainous range disjunct from the Main Range where S. concinna is found.

Figures

FIGURE 7. Scaphochlamys tahanensis. A. Habit. B. Flower. C. Inflorescence. by K. Imin.

FIGURE 8. Scaphochlamys tahanensis. A. Habit. B. Floral bract. C. First bracteole. D. Ovary and calyx. E. Dorsal corolla lobe. H. Lateral corolla lobe. G. Staminode. H. Labellum. I. Stamen front view (I’), back view (I’’), back view (I’’’). J. Stigma side view (J’), front view (J’’). A–J from L.G. Saw FRI 44667 (K).