Amomum villosum, Karunarathne & Yakandawala & Samaraweera, 2014

Karunarathne, Piyal, Yakandawala, Deepthi & Samaraweera, Preminda, 2014, On the occurrence of a new variety of Amomum villosum (Family Zingiberaceae) in Central Hills of Sri Lanka, Phytotaxa 172 (2), pp. 129-132 : 130-131

Amomum villosum var. nov. zeylanicus Karunarathne and Yakandawala

(Fig. 01)

Type:— SRI LANKA, Central Province, Seven Virgin Hills of Central Highlands , 1540 m, 6°53’51.92”N, 80°29’16.69”E 26.07.2011, P. Karunarathne, D. Yakandawala and U. Weerasekara 2576. (Holotype: K, Isotype: PDN) .

This species can be distinguished from all Amomum species by the presence of the following characters. Shortly petiolated leaves, ligule and petiole are of more or less the same length. Ligule tip emarginated with ciliated tips. Leaf petiole can be up to 1 cm. Leaf base attenuate. Inflorescence ovoid and small. Bracts and bracteoles coriaceous and glabrous. Labellum clawed, tip bifid, white color with yellow mid line flanked by two red maroon stripes at either lateral sides. Lateral staminodes reduced to small swellings. Geological separation is also another which helps in diagnosis.

Terrestrial herb forming loose clumps. Leafy shoots 10–15 cm apart, 1.5-1.7 m tall can exceed 2 m, leafless for about 20-45 cm from the base, with 15-45 leaves per shoot. Leafless sheaths 3-5, open but tightly bound to the main axis, yellowish green at young stage, turn dark green with age and sometimes dull green, glabrous. Ligule 0.6-0.9 cm long and 0.8 cm wide, one lobe, truncate- emarginated tip, dark brown-green, glabrous, entire margin. Leaves petiolate, lamina broadly lanceolate, 20-35 × 4-8 cm, green and glossy above, lighter beneath, hairs confined to mid-rib below, acuminate tip and attenuate at the base, margin entire. Inflorescence born on a separate none vegetative subterranean prostrate peduncle, terminal, peduncle covered with red-brown coloured lanceolate-obtuse scaly sheaths: 2-3 × 2-2.5 cm, ciliated at the top margin, sheaths do not overtop the inflorescence but top most sheaths resemble bracts, peduncle terminates in a congested raceme inflorescence with 8-12 flowers, inflorescence ovoid shaped and 5-9 cm long. Bracts; only fertile bracts present, fertile bracts subtending cincini ( L: 3.5 cm, w: 2 cm) with single flowers, pinkish brown, pink spotted along veins, glabrous, all bracts usually oblong-lanceolate and retuse. Bracteoles non-tubular, one lobe, saccate and deeply keeled top to bottom, 11-13 mm long, 4-5 mm wide, glabrous, color similar to bracts but sometimes lighter and spotted pink. Flower 3 cm long, pedicelate, pedicel 5 mm long, 1.5-2 mm diameter, glabrous. Calyx tubular unilaterally split, 12-15 mm long, 5 mm diameter at broadest, translucent white-pink sometimes with a slight pink at the base, glabrous, three toothed, margin membranous and top part sac-like. Corolla tube not exceeding the calyx most of the times equaling, 1.2-1.5 cm long, translucent white with pink spots, glabrous, three corolla lobes, ovate-oblong with saccate- apiculate- concave tips, all three lobes more or less similar in size 10 × 5 mm, translucent white. Lateral staminodes reduced to small swellings at either side of the labellum and sometimes with small projections. Labellum one lobed clawed and narrower at the base, obovate, 13- 15 mm long, 10 mm wide at broadest, apex bifid curved dorsally, white colored, a dark yellow wide strip runs along the mid line and two red-maroon small stripes flanking the yellow line, glabrous. Stamen 10 mm long, anther filamented, filament 5 mm long 2 mm wide, white, anther attached at about 160º, white, anther thecae parallel and diverging at the apex, cream colored, dehiscing longitudinally for its entire length, connective prolonged to a crest, 5 mm wide 3 mm long, margin undulating and curved opposite to the anther, white color, glabrous. Ovary rather elongated, 4-5 mm long, 2-2.5 mm diameter at middle, white- pink, pubescent, trilocular, placentation axile. Style 25-27 mm long keeping stigma just above the anther, white, glabrous, stigma 1.2 mm diameter. Epigynous glands two, not united, 1-1.5 mm long, aprox. 1 mm diameter, with blunt apex, cream to very light brown. Fruits capsules, globose, echinate, 1-1.5 cm. long 1-1.5 cm. wide, greenish yellow colored with maroon-red spines, becoming entirely maroon-red with age, on average 5-10 fruits per infructescence. Seeds rounded, dark brown-black in color, c. 10 per locule.

Phenology:—Flowering- February to May. Usually they start blooming at the first dry period after a wet rainy season and the flowering is synchronized so that most mature individuals in an area flower at the same time. An inflorescence may bear open flowers for three to four weeks and an open flower lasts for only two days.

Distribution, habitat and ecology:—This species is still known only from the type locality which is the Seven Virgin Hills of Peak Wilderness sanctuary. The type was gathered from the valley areas between the second and the third hills. Habitat of the plant is basically the understory of wet montane forests above 1500 m from the sea level, prevailing climatic conditions: temperature ranges from 10 to 20 C, mean annual rain fall of this area is 4000-5000 mm. Besides evidence of being an important understory plant, very little is known about the ecology of this plant.

Etimology:—Epithet z eylanicus stands for Sri Lanka. This is the first record of Amomum villosum from Sri Lanka.

Note:— A. villosum var. z eylanicus can be easily distinguished from A. villosum var. villosum , A. villosum var. xanthioides and A. uliginosum from the following combination of morphological characters. Ligule coriaceous, shorter (always less than 1 cm) and emarginated tip. Leaves petiolated, petiole can be up to 1 cm and pubescent under. Lamina lanceolate to elliptic and pubescent along the mid-rib below. Bracts and bracteoles non-tubular and glabrous. All the corolla lobes are similar in size. Labellum comparatively smaller and pubescent within throat. No hairs on capsule.

Proposed IUCN status: VU B1ab(iii). This species has been recorded only from three localities in a restricted forest area, therefore the area of occurrence is estimated to be well under 20, 000 km 2. Moreover, the location where the species has been recorded is under human influence and changes in the habitat is quite frequent. Hence, the species is estimated to be Vulnerable under criterion B1.