REVISION OF AMORPHOPHALLUS BLUME EX DECNE. SECT. AMORPHOPHALLUS (ARACEAE) IN INDIA

Amorphophallus Blume ex Decne. sect. Amorphophallus in India is revised. It is the smallest of the three sections in India with five species, viz. A. hirsutus Teysm. & Binn., A. kachinensis Engl. & Gehrm., A. longistylus Kurz, A. napalensis (Wall.) Bogner & Mayo and A. paeoniifolius (Dennst.) Nicolson. Amorphophallus paeoniifolius is the widely distributed species in India with two varieties, viz. A. paeoniifolius var. paeoniifolius, and var. campanulatus (Decne.) Sivad. Amorphophallus longistylus is the only species of the section endemic to India. Introduction Amorphophallus Blume ex Decne. sect. Amorphophallus (Araceae) is the smallest of the three sections represented in India. Revisions of the other two sections, viz. Rhaphiophallus and Conophallus have been carried out recently by Jaleel et al. (2011, 2012). Engler (1911) in his revision of the genus treated Amorphophallus campanulatus Decne. [=A. paeoniifolius (Dennst.) Nicolson] under the section Cundarum Engl. which is a renaming of Candarum Rchb. ex Schott. According to Engler (1911), composition of the name ‘Candarum’ was improper and he renamed it as ‘Cundarum’ stating that the name is derived from the Indian name ‘Kunda’ (= Amorphophallus campanulatus) to which the suffix ‘arum’ was added resulting in ‘Kundarum’ and written as ‘Cundarum’. He considered it as a new name with his authorship. But as per Art. 60.1 of ICN (McNeill et al., 2012) the original spelling of a name or epithet is to be retained, and hence the name Cundarum Engl. is treated as illegitimate. Engler (1911) included Amorphophallus campanulatus, the type of the genus Amorphophallus under the section Cundarum Engl. As per Art. 22.1. of ICN, the name of any subdivision of a genus that includes the type of an adopted, legitimate name of the genus to which it is assigned is to repeat that generic name unaltered as its epithet, and accordingly the correct name of the section of Amorphophallus that includes Amorphophallus campanulatus [=A. paeoniifolius] should have been Amorphophallus sect. Amorphophallus, and it is used in the present study. Out of the seventeen species of Amorphophallus included in Flora of British India by Hooker (1894), only eight were reported to be occurring in India and Amorphophallus longistylus Kurz ex Hook. f., A. campanulatus (=A. penoniifolius) and A. dubius Blume (=A. penoniifolius) are among those belonging to the section Amorphophallus as per the present standards adopted for species delimitation. Engler (1911) in his monographic work included A. longistylus under the section Conophallus, and A. napalensis was treated under the genus Thomsonia which was later transferred to Amorphophallus by Bogner et al. (1985). Since Engler’s work, several new species have been discovered from various parts of India. Brief accounts on earlier taxonomic work on Indian Amorphophallus have been provided by Jaleel et al. (2011, 2012). The present article is the third and final part of revision of the genus Amorphophallus in India. Materials and Methods Present address: Department of Botany, Sir Syed College, Taliparamba, Kannur-670 142, Kerala, India Department of Botany & Microbiology, College of Science, King Saud University, P. O. Box 2455, Riyadh11451, Kingdom of Saudi Arabia Corresponding author: Email: drmsivadasan@rediffmail.com


Introduction
The methodology adopted in earlier works (Jaleel et al., 2011(Jaleel et al., , 2012 have been followed in the present work. Extensive and exhaustive field explorations covering all seasons were made all over India for collection and recording relevant data of the specimens. Indian specimens available at various major herbaria such as ASSAM, BM, BSA, BSD, BSHL, BSI, CAL, CALI, DD, GH, JCB, K, KFRI, L, M, MH, PBL, TBGT and US were consulted, and representative specimens were cited. Blume ex Decne., Nouv. Ann. Mus. Hist. Nat. 3: 366 (1834), nom. cons. [Taxon 31: 310 (1982) (Fig. 1). Type: West Sumatra, Soeka Menanti, Ophir, (no date), Buennemeijer 1019 (Neotype: BO). Tubers depressed-globose, 4.5-8.5 cm diam. and 2.5-5.0 cm thick in vegetative phase; c. 11 cm diam. and 7 cm thick in reproductive phase; root scars thickened, annulate. Petiole 73-82 cm long, pale green with small blackish green irregular specks and mottles with minute dark green spots in between, paler towards the tip, extreme base with purplish blue hue; some petioles with pale green background having large irregular blackish green patches with light greyish margin, and minute greenish spots in between, and paler towards the tip. Leaflets sessile, ellipticlanceolate, large leaflets 11-17 × 3-5 cm, small 6.2-10.5 × 1.8-4.0 cm, acuminate at apex, base unequal, decurrent on rachis, greenish above and pale below. Peduncle short, 3.0-5.5 cm long, greenish in colour. Spathe campanulate, broadly triangular-ovate, c. 17.5 × 26.0 cm, basal tube separated from limb by a constriction, tip acute, margin undulate; tube c. 7.5 cm diam. and 5.5 cm high, greenish outside with few small white mottling, smooth, pale greenish inside, purplishorange or maroon at extreme base, rough, irregularly and longitudinally rugose and verrucate; limb c. 9.5 cm long spreading, up to c. 12 cm diam., purplish outside and inside. Spadix shorter than spathe, c. 12.5 cm long; sessile, female zone c. 3.3 cm long; male zone c. 3.8 cm long; appendix c. 3 cm high and c. 5.5 cm diam. Female flowers dense, each flower c. 10 mm high; ovary subglobose, pale greenish, c. 4 mm diam. and 3 mm high, 2-3-locular, each locule with a single basal anatropous ovule; style c. 5 mm long, purplish; stigma 2-3-lobed, c. 2.5 mm diam., pale yellowish. Male flowers dense, pale yellowish with purplish tinge at top of connectives; each c. 2 mm high, sessile, inconspicuously 2-lobed. Spadix-appendix subglobose, light purplish yellow, rough, abruptly narrowed to a cylindric truncate column of c. 1.8 cm high and 0.9 cm diam., light purplish yellow, rough; cylindric column and its basal surrounding portion covered with stiff slender bulbous-based papillae; papillae on cylindrical column smaller compared to that of basal neighbouring portion; appendix becomes unevenly bullate after anthesis. Notes: Amorphophallus hirsutus resembles A. paeoniifolius and A. prainii in general vegetative morphology and inflorescence, especially during the early stages. It differs from the latter two by having a subglobose appendix with a cylindric apical column covered with short stiff papillae. There is no other Indian species with hairs on the spadix-appendix.
Notes: The close morphological similarities of Schena (Hort. Malab. 11: 35, t. 18. 1692) and Mulenschena (Hort. Malab. 11: 37, t. 19. 1692) of Rheede and unawareness of the existence of an earlier legitimate epithet for Mulenschena, the name Amorphophallus campanulatus Decne. had been used for both the cultivated and wild elements represented by Schena and Mulenschena respectively. Realizing the existence of an earliest epithet for Amorphophallus campanulatus, Nicolson (1977) made a combination of name, viz. Amorphophallus paeoniifolius (Dennst.) Nicolson, as applying to Amorphophallus campanulatus (sensu lato). The wild and cultivated elements differ in many respects even though they resemble in general appearance and many other characteristics; and hence they are treated as two distinct varieties of A. paeoniifolius. Backer (1920) recognized the wild and cultivated elements as belonging to two distinct subspecific taxa and assigned the rank 'hoofdgroep' which is not valid. Backer and Bakhuizen van den Brink (1968) replaced the rank 'hoofdgroep' with 'forma'. Detailed accounts on the identity and nomenclature of Rheede's Schena and Mulenschena have been provided by Suresh et al. (1983).
Distribution: India, Sri Lanka and Pacific islands. In India, found in almost all States.
Notes: The confusion in nomenclature of the wild and cultivated varieties of Amorphophallus paeoniifolius has been sorted out by Suresh et al. (1983) while providing correct identity of aroids described by Rheede (1692).
Amorphophallus paeoniifolius var. campanulatus representing the cultivated variety differs from var. paeoniifolius in texture of petiole, characters of female flowers and spadix-appendix. The former is having smooth or slightly rough greenish petiole with white blotches, leaflet-bases not decurrent to the junction of the petiolules, style of pistil more than thrice the height of the ovary, spadix-appendix round-obtuse to broadly hemispherical with height less than its breadth, and no fruit-setting. The latter is having strongly muricate purplish petiole with light pinkish blotches, leaflet-bases strongly ducurrent usually to the junction of the three main rachises, style more or less double the height of the ovary, spadix-appendix long-conoidal, height more than its breadth, and fruit-setting.
Distribution: India, Sri Lanka, Java and Myanmar. In India, common in all States. Widely cultivated for the edible tubers.

Taxonomic Analysis
In India the genus Amorphophallus comprises three sections, viz. Amorphophallus sect. Amorphophallus, sect. Rhaphiophallus, and sect. Conophallus. Jaleel et al. (2011) stated the genus to have three sections namely A. sect. Candarum, sect. Conophallus and sect. Rhaphiophallus. But Engler's (1911) inclusion of A. campanulatus (=A. paeoniifolius), the type of the genus under sect. Candarum ("Cundarum") rendered the sectional name illegitimate. The sectional name which included the type of the genus has been correctly recognized here as A. sect. Amorphophallus.
Amorphophallus sect. Rhaphiophallus is the largest of the three sections of the genus and is represented in India by eight species (Jaleel et al., 2011) Among the species of A. sect. Amorphophallus, the two species, viz. A. hirsutus and A. kachinensis are new addition to the flora of India and they have been collected from Great Nicobar Island of Andaman and Nicobar Islands, and Arunachal Pradesh respectively, and their discoveries formed first reports of their distribution in India. Amorphophallus longistylus was rediscovered and collected from Andaman Islands after 131 years from the time of its first collection.
Amorphophallus paeoniifolius is the widely distributed species in India represented in all states. During the present study it was found that maximum number of species of the section occur in Arunachal Pradesh and Andaman and Nicobar Islands. Arunachal Pradesh has 3 species, viz. A. kachinensis, A. napalensis and A. paeoniifolius, and Andaman and Nicobar Islands have 3 species, viz. A. hirsutus, A. longistylus, and A. paeoniifolius. Amorphophallus longistylus is strictly endemic to Andaman Islands with restricted distribution and according to the criteria D of section V of IUCN (2012), it is considered as Critically Endangered (CR).
The fast and indiscriminate deforestation and destruction of natural habitats of the species render most of the endemic species endangered and lead to extinction. Proper monitoring of habitats and distribution are essential for conservation of species of the genus Amorphophallus which comprised wild relatives of widely used and economically important cultivated species.