Impatiens theuerkaufiana Ratheesh & Sivadasan, 2013

Ratheesh Narayanan, M. K., Joseph, Jayesh P., Kumar, N. Anil, Sivadasan, M. & Alfarhan, Ahmed H., 2013, Impatiens theuerkaufiana (Balsaminaceae), a new scapigerous species from the Western Ghats, India, Phytotaxa 83 (1), pp. 54-60 : 55-57

Impatiens theuerkaufiana Ratheesh & Sivadasan , sp. nov. ( Figs. 1 & 2 )

The new species resembles I. dendricola and I. agumbeana , but differs by having the lower sepal with a short spur up to 5 mm long, the dorsal petal transversely elliptic, basally and distally bilobed, wavy-margined, the lateral united petals non-auricled, and a tuberculate seed coat. It differs from I. agumbeana by having pendulous linear lanceolate leaves, white flowers with a short pedicel up to 3.5 cm long, and ellipsoid capsules; and from I. stocksii by having a long petiole of 5–8 cm, an elliptic lanceolate leaf lamina, longer pedicels of 2.0– 3.5 cm, and a pouch-like short spur.

Type:— INDIA : Kerala: Wayanad district, Chembra hills, 11 ° 30.716´N, 76 ° 06.239´E, ± 1900 m a.s.l., 19 September 2006, Narayanan MSSH 2316 (holotype MH!, isotypes Community Agrobiodiversity Centre (CAbC)– MS Swaminathan Research Foundation ( MSSRF) herbarium, Wayanad!) .

Epiphytic, scapigerous perennial herbs, 10–20 cm tall, rootstock tuberous; tubers whitish, globose. Leaves 1 or 2, radical, petiolate, pendulous, membranous; petiole 5–8 cm long, pale pink, slender, glabrous; lamina 10.0–16.0 x 1.5–3.0 cm, elliptic-lanceolate or lanceolate, apex acute, base oblique, attenuate, faintly crenate along margins, crenatures minutely apiculate, adaxially pale green, abaxially pale pink, glabrous; nerves 4–6 pairs, prominent and pale pink below. Inflorescence a simple racemose scape, semi-pendulous; peduncles slender, terete, 12–20 cm long, glabrous, 5–8-flowered; flowers distal, each 1.3–1.5 x 1.0– 1.3 cm, white with yellow patches of papillae near the centre; pedicel 2.0– 3.5 cm long, elongating in fruiting stage; bract broadly ovate, ca. 8 x 4 mm, concave, pale green, glabrous; sepals white, glabrous; lateral sepals ca. 2.0 x 1.2 mm, broadly ovate, entire; lower sepal broadly elliptic, spurred; spur straight, pouch-like, 3.5–5.0 mm long, white, glabrous; dorsal petal transversely elliptic, 3.5–4.0 x 5.0–6.0 mm, basally and distally bilobed, margins wavy, glabrous; lateral united petals 3-lobed, non-auricled, 1.0– 1.2 cm long, white with a tuft of yellow papillae a little above the base of the inner margin; basal lobes largest, ca. 4 mm long, bent upwards, broadly obovate; middle lobe smaller, ca. 2 mm long; distal lobe narrow, straight with sub-truncate tip, 3–4 mm long; stamens 5, connate; filaments white; ovary pale yellow, broadly ellipsoid, acute at apex, glabrous. Capsule broadly ellipsoid, acute, ca. 8 mm long, glabrous; seeds up to 70, minute, tuberculate, with a dense tuft of hairs at both ends.

Phenology: —Flowering from early July with peak in August; fruiting in September.

Eponymy: —The specific epithet is in honor of Mr. Wolfgang D. Theuerkauf, founder of the Gurukula Botanical Sanctuary, Alattil, North Wayanad, Kerala and an ardent naturalist and botanist who devoted his life for conservation of wild plants of Western Ghats, and creating awareness and imparting education on nature, natural resources, and conservation.

Distribution, habitat and ecology: — Impatiens theuerkaufiana grows in montane evergreen forests at elevations of 1,900 –2,000 m. It is known only from the Chembra hills of the Wayanad district, Kerala. Small populations of this species are distributed in two montane evergreen forests in the area. The species is usually seen as an epiphyte on the moss-covered trunks of evergreen tree species. Density of the individuals is higher on trees inside the shola forest. The delicate species appears with the onset of monsoon and the leaves perish within a short period, even with just a week-long non-rainy period during monsoon season. The host-tree species include Holigarna nigra Bourdillon (1904: 95) , Ixora sivarajiana Pradeep (1997: 315) , Symplocos racemosa Roxburgh (1832: 539) , Syzygium hemisphericum ( Wight 1841: 14) Alston in Trimen (1931: 115), etc. The associated species include Belosynapsis vivipara Fischer (1928: 254) , Impatiens jerdoniae Wight (1850: 15 , t. 1602), I. parasitica Beddome (1859: 66) , Medinilla malabarica Beddome (1868 –1874: 33), Oberonia brunoniana Wight (1851: 3 , t. 1622), O. nayarii Ansari & Balakrishnan (1990: 17) , O. tenuis Lindley (1859: 3) , etc.

Interrelationships: — Impatiens theuerkaufiana resembles I. dendricola Fischer (1935: 157) in its pendulous habit, white flowers, 3-lobed lateral united petals with a tuft of papillae a little above the base and near the centre along the inner margin, and seeds with tufts of hairs at both ends. The length of the peduncle and pedicel, shape and size of the lateral sepals, dorsal petal, spur and lateral united petals and texture of seeds distinguish the new species from the latter. The new species has entire, broadly ovate lateral sepals and a basally and distally bilobed, transversely elliptic dorsal petal with wavy margins in contrast to the falcateovate lateral sepals with deeply lobed base, and entire dorsal petal of I. dendricola . Impatiens theuerkaufiana has also a short straight pouch-like spur of less than 5 mm in contrast to the 1.0– 1.5 cm long, strongly curved, clavate spur of I. dendricola . The lateral united petals of the new species are less than 1.5 cm long, strongly recurved, basal lobes broadly obovate of ca. 4 mm long with wavy margins, and seeds are tuberculate, while in I. dendricola the lateral united petals are up to 2 cm long with a straight, strap-shaped, apically rounded basal lobes of ca. 8 mm length, and seeds with a muriculate surface. The new species also resembles I. agumbeana Bhaskar & Razi (1938: 382) in some of its characters such as the short spur less than 5 mm long, lateral united petals with a large recurved basal lobe and seeds with dense tufts of elongated hairs at both ends. It differs by its pendulous lanceolate leaves, flowers with pedicels up to 3.5 cm long, lateral united petals without a dorsal auricle, and an ellipsoid capsule, whereas I. agumbeana shows ovate leaves with an acute base, laterally united petals with a prominent dorsal auricle, flowers with pedicels up to 20 cm long, and an ovoid capsule. Impatiens stocksii Hooker & Thomson (1859: 119) exhibits some resemblance with the new species in its white flowers with yellow patches of papillae, but differs in its broadly ovate or elliptic to orbicular leaves with a short petiole of 1.0– 4.5 cm, short scapes of 3.0– 8.5 cm with flowers having short pedicels of 0.9–1.3 cm and without a spur. Diagnostic morphological characters of Impatiens theuerkaufiana and the related species are provided in Table 1.

Additional specimen examined (paratype): — INDIA . Kerala: Wayanad District, Chembra hills, N 11 ° 30.716´E 76 ° 06.239´, ± 1900 m, 20 August 2009, Narayanan MSSH 4026 (Herbarium of CAbC-MSSRF, Wayanad!) .

Figures

FIGURE 1. Impatiens theuerkaufiana. A. Habit. B. Bract. C. Single flower. D. Lateral sepal. E. Lower sepal with spur. F.Dorsal petal, dorsal view. G. Lateral united petals. H. Stamens. I. Pistil. J. Fruit. K. Seed. Drawings by Jayesh P. Joseph from living specimens.

FIGURE 2. Impatiens theuerkaufiana. A. Habit. B. Inflorescence. C. Flower. D. Young fruit. Photos by M. K. Ratheesh Narayanan.