Colocasia kachinensis S.S.Zhou & J.T.Yin, sp. nov.

Zhou, Shi-Shun, Quan, Rui-Chang, Li, Ren, Liu, Qiang & Yin, Jian-Tao, 2020, Colocasia kachinensis, a new species of Araceae from Myanmar, PhytoKeys 138, pp. 41-47 : 41

Colocasia kachinensis S.S.Zhou & J.T.Yin, sp. nov. Figures 1 , 2 , 3 , 4

Colocasia sect. Caulescentes Engl.

Diagnosis.

The morphological characteristics of C. kachinensis are closely related to those of C. menglaensis but C. kachinensis differs in having an erect stem (see Fig. 3 ), no stolons, smaller leaf and inflorescence and glossy petiole and peduncle.

Type.

MYANMAR. Kachin State. Putao Township, Hponkanrazi Wildlife Sanctuary, Namse Village, 97°18'30.3"E, 27°17'49.7"N, alt. 1238 m, 26 April 2016, Jian-Tao Yin 2483 (Fig. 2 ) (holotype, HITBC!, isotype: HITBC!)

Description.

Terrestrial perennial herbs with an erect stem. Plant 54 cm high; erect stem 12 cm long, 3 cm in diam. Leaves 3-4; petiole cylindric, pale greenish, glossy, 32 cm long, 0.6 cm in diam., sheath 16 cm long, 6 cm in diam.; leaf blade oblong-ovate, peltate, 18 cm long, 12 cm wide, upper surface glossy green, lower surface greyish-white; primary lateral veins pinnate, 5 pairs, pale green on upper surface, white and raised on the lower surface. Inflorescences (1-)3(-4) emerging when the leaves unfold, 27 cm long; peduncle cylindrical, pale green, glossy, 17 cm long, 0.5 cm in diam. Spathe constricted in the lower third, lower convolute part (tube) pale green, farinose, 3.5 cm long, 1.5 cm in diam., nearly cylindrical; lamina oblong-lanceolate, erect during early blooming period, pale yellow, 6.5 cm long, 3 cm wide. Spadix 7 cm long, female zone 2.5 cm long, 0.8 cm in diam.; sterile zone between female and male zones, cylindrical, white, 0.8 cm long, 0.3 cm in diam.; male zone, white, 2 cm long, 0.6 cm in diam.; appendix white, long conical, wrinkled, 2 cm long, 0.4 cm in diam. Flowers unisexual, perigone absent. Male flower: 1-4-androus, stamens connate in truncate synandrium, thecae lateral, oblong-lineal, dehiscing by apical pore. Female flower: ovary ovoid to oblong, 1 mm long, unilocular; ovules many, 42-58, n = 2, fusiform, translucent; placentae 3-5, parietal; stylar region absent; stigma discoid-capitate; berry not seen.

Phenology.

Flowering in March to April. Fruiting unknown.

Distribution and habitat.

C. kachinensis is so far known from a single population in Kachin State, northern Myanmar, where it grows in humid dense mountain rain forest (cover degree 70%) at alt. 1100-1400 m. In the same habitat, other plants encountered were C. menglaensis , Liquidambar excelsa , Terminalia myriocarpa, Caryota urens , Magnolia sp., Musa itinerans , Saprosma ternate , Dendrocalamus sp., Phrynium rheedei .

Etymology.

The species is named after the holotype region, Kachin State, Myanmar.

Additional examined specimens (Paratype).

MYANMAR. Putao Township, Kachin State, alt. 1300 m, 26 April 2016, Jian-Tao Yin 2482 (paratype: HITBC!)

Figures

Figure 1. C. kachinensis. A plant B inflorescence C lower surface of leaf D spadix.

Figure 2. Holotype of C. kachinensis. See text for collection details.

Figure 3. Stem of C. kachinensis and morphological comparison between C. menglaensis and C. kachinensis. A stem of C. kachinensis B lower surface of leaf x 100 of C. menglaensis C lower surface of leaf x 100 of C. kachinensis.

Figure 4. Male flower of C. kachinensis. Drawn by Mr. Bo Pan from the holotype. A Male part of spadix B 1 - androus flower C 2 - androus flower D 4 - androus flower E 3 - androus flower.