Cinnamomum nilagiricum Geethakum., Pandur. & Deepu, 2015

Geethakumary, M. P., Pandurangan, A. G. & Deepu, S., 2015, A new species of Cinnamomum (Lauraceae) from Nilgiris, southern Western Ghats, India, Phytotaxa 224 (3), pp. 283-290 : 283-289

Cinnamomum nilagiricum Geethakum., Pandur. & Deepu , sp. nov. ( Fig. 1 , Fig. 2 & Fig. 3 )

Type:— INDIA. Tamil Nadu: Nilgiri Distr., Nadugani, 11°28’36.5”N & 76°25’13.1”E, ± 965 m, 07 November 2012, Geethakumary & A. G. Pandurangan 75229 (holotype TBGT!, isotypes CAL!, MH!, K!).

Trees, 8–12 m high; trunk buttressed at base; bark brown; branchlets slender, terete, covered with apressed hairs when young; terminal bud densely sericeous. Leaves opposite or subopposite, rarely alternate, ovate to elliptic to lanceolate, 7.5–12.5 x 2.6–4.3 cm, coriaceous, smooth, dark green above, light green below, glabrous, with strong smell of camphor; shortly attenuate at the base, acute to long acuminate to caudate at the apex, acumen to ca. 1.5 cm; midrib slender, prominent below, 2 sub-basal lateral nerves reaching ¾ of the lamina, tertiary nerves parallel, 2–3 mm apart, finer venation reticulate, impressed adaxially, raised abaxially; petioles slender, 0.5–1.0 cm long, slightly canaliculate. Panicles terminal or from the axils of terminal leaves or extra axillary on new growth, many flowered, minutely sericeous; main peduncle slender, 3.5–7 cm long; branches 2–4, 5.5–9.5 cm long; pedicels 4–5 mm long, slender. Flowers greenish white, 9–12 mm long, 2.5–3 mm across, pubescent. Tepals 6 in 2 whorls of 3 each, ovate, ca. 3 mm long, minutely sericeous, sparsely within, densely towards the base and margin, less upwards, apex obtuse to acute. Stamens 9 in 3 whorls of 3 each; whorls I and II with anthers sub-rectangular, 1–1.2 mm long, 4-locellate, fleshy, introrse; filaments ca. 1 mm long, hirsute; whorl III extrorse, ca. 2 mm long, anthers oblong, 4-locellate; glands subsessile, broadly ovate, ca. 0.5 mm long, attached near the basal portion of the filaments; staminodes shorter than the anthers, ca. 1 mm long, cordate, stipes pilose. Ovary ellipsoid, ca. 1 mm long, glabrous; style ca. 1.2 mm long, rather thick; stigma peltate. Fruits ellipsoid, ca. 8 mm long; cupule cup shaped, base conical, with remnants of tepal bases.

Phenology:—Flowering and fruiting was observed from November to March.

Etymology:—The specific epithet “ nilagiricum ” refers to the type locality, the Nilgiri district in Tamil Nadu, India. The very name of the habitat “Nilgiris” with literary meaning “blue mountains” has originated from the spectacular appearance of blue flower clad mountains of the Nilgiri plateaus within the state of Tamil Nadu. The blue flowers are borne by an endemic species of Strobilanthes kunthianus (Nees) T. Anderson (1867: 465) , locally known as “kurinji” which flowers gregariously once in 12 years and gives the wonderful blue cover to the mountains periodically.

Distribution:—(i) Cinnamomum nilagiricum is distributed in the Nilgiri Mountains, part of the southern Western Ghats, located in Tamil Nadu, India ( Fig. 3-D ). The new species grows in shola forests along streams in association with Aporosa acuminata Thwaites (1861: 288) , Cinnamomum wightii Meisn. (1864: 11) , Neolitsea umbrosa (Nees) Gamble (1914: 79) , Osyris lanceolata Hochst. & Steud. (1832: s.n.) etc.

(ii) While scrutinising the wild Cinnamomum species grown in the natural forest, located at Jawaharlal Nehru Tropical Botanic Garden and Research Institute (JNTBGRI), a single medium sized tree belonging to C. nilagiricum has been identified. Therefore we suppose that this new species might have shown either disjunct distribution or still there may be some unidentified populations in inaccessible areas of Western Ghats between Nilgiris in the north to Agasthyamalai region in the south, where JNTBGRI is located.

Conservation status:—The new species has been located in two distinct micro-endemic centres i.e., Nilgiri Plateaus and Agasthyamalai region, which are separated by Palghat pass. Though the Extent of Occurrence (EOO) is> 20,000 km 2, the habitable sites within the EOO are restricted to the above mentioned localities and the Area of Occupancy (AOO) is still less than 0.5 km 2. At the type locality we could locate only 4 reproductively mature individuals. Therefore, as per preliminary conservation assessment, we recommend that this species may be treated as Critically Endangered CR-B2a; D ( IUCN, 2012a &b, 2013). Since the type locality is within the Biosphere Reserve and the other locality is within a Botanic Garden, the species receives adequate protection.

Discussion:— Cinnamomum nilagiricum shows some morphological similarities with C. dubium Nees (1831: 73) and C. riparium Gamble (1925: 128) but is distinct in a number of characters viz., buttressed trunk, strongly camphor scented leaves, whorl III stamens with 4-locellate anthers and cordate staminodes. The main character state differences between these three species are summarized in Table 1 and Fig. 4 .

The new species can be recognized by its buttressed trunk and whorl III stamens with 4- anthers, a character normally observed in species. Kostermans (1983) while revising the genus for South India made diagrams of whorl III anthers with two fertile and two degenerative cells, which have been mistaken by some taxonomists as 4-locellate anthers, because this character is widely prevalent in other parts of the world ( Lorea-Hernández 1996). Fruit set in this species is rare due to infestation by caterpillars during flowering that completely destroys the ovary.

For confirming the novelty of the species, C. nilagiricum was compared with the recently described camphor scented C. agathyamalayanum Robi et al. (2014: 1012) from Kerala. Cinnamomum nilgiricum has ovate to elliptic to lanceolate leaves with shortly attenuate base and acuminate to caudate apex, a many flowered inflorescence, whorl III stamens with 4-locellate anthers, cordate staminodes and an ellipsoid ovary, whereas in C. agasthyamalayanum the leaves are elliptic to lanceolate with acute base and sub-acuminate to attenuate apex, a few flowered inflorescence, whorl III stamens with 2-locellate anthers, sagitate staminodes and an obovoid ovary. On critical study of type specimens (Isotype KFRI 11122!; Paratype KFRI 11123!) and protologue, the latter was found to have additional morphological characters, such as petioles 1–1.5 cm, extra-axillary few flowered cymose panicles, tepals and anthers glandular, stamens with densely pilose filaments, anthers broadly oblong, whorl III stamens with 2-locellate anthers and stipitate basal glands, and sagittate staminodes (addition to the protologue in boldface).

Additional specimens examined:— INDIA. Kerala: Thiruvananthapuram Distr., JNTBGRI, 08 o 45’22.8”N & 77 o 01’41.0”E, ± 144 m, 14 January 2014, Geethakumary & A. G. Pandurangan 75888. Tamil Nadu: Nilgiri Distr., Nadugani 11 o 28’36.5”N & 76 o 25’13.1”E, ± 965 m, 01 February 2014, Deepu Sivadas 78679 (TBGT)

Figures

FIGURE 1. Cinnamomum nilagiricum sp. nov. A. Flower, B–C. Tepals, D–E. Stamens of outer whorl, F–G. Stamens of inner whorl, H. Staminode, I. Pistil. (Photos: Deepu)

FIGURE 2. Cinnamomum nilagiricum sp. nov. A. A twig, B. Flower, C–D. Tepals, E–F. Stamens of outer whorl, G–H. Stamens of inner whorl, I. Staminode, J. Pistil. (Drawn from Holotype by Deepu)

FIGURE 3. Cinnamomum nilagiricum sp. nov. A. Tree in full bloom, B. Flowering twig, C. Fruit, D. Distribution map, E. Trunk. (Photos: Deepu)

FIGURE 4. Type sheets of A. Cinnamomm nilagiricum sp. nov., B. Cinnamomum dubium Nees, C. Cinnamomum riparium Gamble, D. Cinnamomum agasthyamalayamum Robi, Sujanapal & Udayan.