Friday, July 29, 2016

[Botany • 2016] Cryptocoryne aura • A New Species (Araceae) from West Kalimantan, Indonesia

Cryptocoryne aura 
  Wongso & Ipor 

A new species, Cryptocoryne aura Wongso & Ipor, from West Kalimantan, Indonesia, is described and illustrated. It differs from other Cryptocoryne species primarily by having a transparent, ciliate membrane along the leaf margin and a short spathe with a yellow, forward-twisted limb. It has a chromosome number of 2n = 26, which has not hitherto been recorded within the genus. The morphology of the germinating seed is unique within the genus, the embryo emerging c. ⅓ from the distal end of the seed with 3(or 4) plumulary processes (prophylls).

Keywords: Araceae, Cryptocoryne, aroids, taxonomy, new species, chromosome number, seedlings, Indonesia, Borneo, Kalimantan

 Cryptocoryne aura Wongso & Ipor, sp. nov.

Holotype: Indonesia, Kalimantan Barat, West Kalimantan, Kabupaten Sekadau, Kecematan Nanga Taman, 26 Feb 2015, S. Wongso & I. B. Ipor SW1508 (BO; isotypes: C, L, M, SAR, Herbarium Universiti Malaysia Sarawak).

Diagnosis — Cryptocoryne aura differs from all other Cryptocoryne species by having the leaf blade margin with a distinct, whitish, slightly transparent, undulate membrane with whitish, short, ciliate trichomes. The germinating seed is unique within the genus in that the embryo emerges c. ⅓ from the distal end of the seed and bears 3(or 4) plumulary processes (prophylls). Its chromosome number of 2n = 26 has hitherto not been recorded for Cryptocoryne

Fig. 2. Cryptocoryne aura — A: habitat at type locality with slower-flowing water; B: close-up of plants in A.
 Photographed on 26 February 2015 by S. Wongso.

Fig. 3. Cryptocoryne aura, close-up of plants in Fig. 2. — A: newly opened spathes showing subobliquely twisted limb; B: older spathes showing forward-twisted limb. 
Photographed on 26 February 2015 by S. Wongso.

Etymology — The epithet alludes to the well-developed, slightly transparent, whitish membrane surrounding the leaf margin, which is likened to an aura.

Remarks — Cryptocoryne aura has a growth stature resembling that of Celliptica Hook. f. (Peninsular Malaysia) and Cbogneri Rataj (Sri Lanka) in having all parts of the plant of small size and a rosette of many leaves, indicating that the plants are situated in shallow water with the leaf blades just below the water surface. This common rosette phenomenon in these species is no doubt an adaptation to similar habitat niches and does not necessarily reflect a close phylogenetic relationship.

The morphology of the germinating embryo is unique for the genus, with the seeds having a rather thin and pointed distal end, with the embryo breaking through the testa c. ⅓ from this end with 3(or 4) plumulary processes (prophylls); the primary root emerges from the distal end of the seed, while secondary roots emerge along with the plumulary processes.

 Suwidji Wongso, Isa B. Ipor, Cheksum S. Tawan, Hendra Budianto, Jan D. Bastmeijer and Niels Jacobsen. 2016. Cryptocoryne aura (Araceae), A New Species from West Kalimantan, Indonesia. Willdenowia. 46(2); 275-282. DOI: 10.3372/wi.46.46209