Burmannia munnarensis Dani & Nampy, 2021

Francis, Dani, Mohan, Vishnu, Venugopal, Divya K. & Nampy, Santhosh, 2021, Burmannia munnarensis (Burmanniaceae) a new species and rediscovery of B. indica after 110 years from southern Western Ghats, Kerala, India, Phytotaxa 507 (1), pp. 105-112 : 106-108

Burmannia munnarensis Dani & Nampy sp. nov. ( Figs. 1 , 4 ).

The new taxon is morphologically close to Burmannia indica Jonker but differs by the narrow flower wings (0.3–0.5 mm vs. 1.5–6 mm), nature of the perianth lobes (involute vs. not involute), length of the perianth tube (5–8 mm vs. 10–13 mm) and inflorescence (rarely branched, 1–4 flowered vs. branched at the top, 1–8 flowered).

Type:— INDIA. Kerala: Idukki district, Munnar, way to Rajamala , ± 1355 m a.s.l., 10°08′00.2′′ N, 77°03′22.5′′ E, 18 November 2020; Dani Francis, Vishnu Mohan & Santhosh Nampy 173331 (holo CALI, iso CAL) .

Annual, erect, chlorophyllous herbs, 8–18 cm tall. Roots fibrous, short. Stems slender, seldom branched, green, glabrous. Radical leaves absent; cauline leaves appressed, scale like, linear-lanceolate, 2–3.5 mm long, cuneate at base, entire at margin, acute-acuminate at apex, greenish, glabrous, single veined. Bracts lanceolate, ca. 2.5 × 0.8–1 mm, obtuse at apex, green, glabrous. Inflorescence rarely branched, 1–4 flowered. Flowers bisexual, 10–15 × 2–5 mm, narrowly 3-winged, sessile or shortly stalked; stalk 1–5 mm long, glabrous. Perianth pale purple; perianth wings half elliptical, 8–11 × 0.3–0.5 mm, running from the base of the limb to the base of the ovary and decurrent along the pedicel, rounded at apex, glabrous; perianth tube cylindrical, 5–8 × 1–1.5 mm; outer perianth triangular, 1–1.5 × ca. 0.6 mm, acute at apex; margin single, involute, slightly thick, purple, glabrous; inner perianth erect, narrow, linear, 0.5–1 mm long, acute at apex, margin single, slightly involute, pale purple, glabrous. Stamens 3, sessile in the perianth throat, ca. 1 mm long, yellow; anthers 2, thecae lateral, connective with two curved, divergent, obtuse, apical crests, and an obtuse, basal spur. Gynoecium 9–15 mm long; ovary 3–7 mm long, obovoid, tricarpellary, syncarpous with axile placentation, glabrous; ovules many, green; style filiform, ca. 6 mm long, glabrous; stigma trifid, funnel shaped, subbilabiate, style with stigma 7–8 mm long. Capsules obovoid, 3–7 mm long, truncate at base, dehiscing in transverse slits, glabrous. Seeds numerous, obovate, 0.1–0.3 mm long, slightly curved; testa spirally twisted.

Distribution and Ecology: —Known only from two localities in Idukki district, where it grows as sparse individuals in open wet grasslands and on dripping rocks along with species of Utricularia striatula Sm. (1818: 37) (Lentibulariaceae) and Jansenella griffithiana (Mull.Hal. 1856:14) Bor (1955: 10) (Poaceae) at an elevation of ± 1355 m.

Flowering & fruiting: —Flowering from October to November. Fruiting from November to December.

Etymology: —The specific epithet refers to the type locality ‘Munnar’ of the new species.

Notes: — Burmannia munnarensis also shows some similarity with Burmannia wallichi Hooker f. (1888: 5) in having narrow perianth wings and overall appearance of flowers and lacking radical rosette leaves, but differs by its habit (chlorophyllous, autotrophic vs. achlorophyllous, mycohetrotrophic), flowers (10–15 mm vs. 6.5 mm long), bracts (ca. 2.5 × 0.8–1 vs. ca. 1.5 × ca. 0.5 mm), connectives (two crest at apex vs. without crest at apex), ovary (3–7 mm vs. 2.5 mm long) and perianth wings (8–11 × 0.3–0.5 vs. ca. 4.5 × ca. 0.5 mm).

Additional specimens examined: — INDIA. Kerala: Idukki district, Pettimudi, near Subran shed, ± 1897 m a.s.l., 10° 9’ 39.76”N, 77° 0’ 39.51’ E, 29 December 2019, Dani Francis & Santhosh Nampy 170099 (CALI!) .

Provisional conservation status: — Burmannia munnarensis is known only from two localities with about 50 mature individuals in each population. The extent of occurrence (EOO) of the species is estimated to be less than 50 km 2 and the area of occupancy (AOO) less than 10 km 2. The type locality is located in a tourist destination, and vulnerable to flood. There is a chance of a reduction in the number of plants in the near future. Hence the species is provisionally categorized as Critically Endangered (CR) based on the criteria A3 + B1 + B2 (bii + iii) + C2 (ai) + D ( IUCN 2019).

Burmannia indica Jonker (1938: 161) ( Figs. 2 , 3 , 4 )

Type:— INDIA. Kerala: Travancore, Peermade , December 1909, Meebold, A. 12915 (B0296386, digital image!)

Annual, erect, chlorophyllous herbs, 15–35 cm tall. Roots fibrous, short. Stems slender, profusely branched, pale green-straw coloured, glabrous. Radical leaves absent; cauline leaves appressed, scale like, linear lanceolate, 1–3.5 mm long, cuneate at base, entire at margin, acute-acuminate at apex, greenish, glabrous; 3–5 veined. Bracts lanceolate, 2–4.2 × ca. 1.3 mm, acute at apex, green, glabrous. Inflorescence branched distally, 1–8 flowers on each branch. Flowers bisexual, 10–20 × ca. 5 mm, sessile or shortly stalked; stalk 1–7 mm long, glabrous. Perianth pale purple; perianth wings half elliptical, 10–16 × 1.5–6 mm, running from the base of the limb to the base of the ovary and decurrent along the pedicel, rounded or cordate at apex, glabrous; perianth tube cylindrical, 10–13 × 1–1.5 mm; outer perianth erect, triangular, 1–2 × 1.5–2 mm long, acute at apex, margin single, thick, swollen, purple, glabrous; inner perianth erect, thick, linear, 0.5–1 mm long, acute at apex, margin single, swollen, pale purple, glabrous, white. Stamens 3, sessile in the perianth throat, ca. 1 mm long, yellow; anthers 2, thecae lateral, connective with two curved, divergent, obtuse, apical crests, and an obtuse basal spur. Gynoecium 13–18 mm long; ovary ellipsoid or obovoid, 1–6 mm long, tricarpellary, syncarpous with axile placentation, glabrous; ovules many, green; style filiform, 8 mm long, glabrous; stigma trifid, funnel shaped, sub-bilabiate, style with stigma 5–12 mm long. Capsules obovoid, 1–6 mm long, truncate at base, dehiscing in transverse slits, glabrous. Seeds numerous, obovate, 0.1–0.3 mm long, slightly curved; testa spirally twisted.

Distribution and Ecology: —Endemic to southern Western Ghats of Kerala. The species is found in open and often wet rocky surfaces along with Burmannia coelestis D. Don (1825: 44) (Burmanniaceae) , Utricularia striatula Sm. (1818: 37) (Lentibulariaceae) , and Tripogon bromoides Roth (1817: 2) at an elevation of ± 1200 m.

Flowering & Fruiting: —Flowering from October to November. Fruiting from November to December.

Notes: — Burmannia indica was first described by F.P. Jonker in 1938 in his monograph of Burmanniaceae based on the homogenous collection of A. Meebold in 1909 from Peermade (now in Idukki district of Kerala). Hazra (1988) in Fascicles of Flora of India and Sasidharan (2011) in his Flowering plants of Kerala mentioned the occurrence of this species based on Meebold’s collection and stated that it is endemic to Kerala. There was no subsequent collection of this species anywhere from south India after the original collection by Meebold in 1909 ( Hooker 1888, Gamble 1928, Matthew, 1983). Thus, the present report forms a rediscovery after a lapse of 110 years and proves its existence in the area. The new locality Meenuliyanpara also belongs to the same district but is separated by approximately 270 km from the type locality. Jonker (1938) mentioned B. indica as a saprophytic species, which indicates the mycohetrotrophic nature of the species, but our collection is chlorophyllous and not mycohetrotrophic. It is likely that Jonker didn’t see living material and his description is based solely on Meebold’s specimens. Moreover, the open and often wet habitats of B. indica also indicates an autotrophic nature.

Additional specimens examined: — INDIA. Kerala: Idukki district, Meenuliyanpara , ± 1200 m a.s.l., 9° 99’ 84” N, 76° 86’ 49” E, 29 December 2019, Dani Francis & Vishnu Mohan 164619 (CALI); Ibid., 25 October 2020, Santhosh Nampy 170085 (CALI) .

Provisional conservation status: — Burmannia indica is known only from two localities, with only one of them extant. The number of mature individuals is about 30 in this population. The extent of occurrence (EOO) of the species is estimated to be less than 50 km 2 and the area of occupancy (AOO) less than 10 km 2. Since the only extant locality is a tourist destination, and a flood prone area, it is possible to infer a reduction in the past of the potential habitat of the species. For this reason, the species can be categorized as Critically Endangered (CR) based on criteria B1 + B2 (a + bii + iii) + C2 (ai) + D ( IUCN 2019).

Figures

FIGURE 1. Burmannia munnarensis Dani & Nampy sp. nov., A. Habit; B. Scale leaf; C. Bract; D. Single flower; E. Upper part of flower split open showing perianth lobes and stamens; F. Outer perianth lobes; G. Inner perianth lobes; H. Stamen, see the two lateral thecae, apical crests and basal spur; I. Gynoecium; J. Seeds. (Drawn by Dani Francis from Dani Francis, Vishnu Mohan & Santhosh Nampy 173331).

FIGURE 2. Burmannia indica Jonker, A. Habitat; B. Inflorescence; C. Basal part of the plant, see the absence of radical leaves; D. Scalelike leaves; E. Bract; F. Flowers; G. Upper part of flower split open showing perianth lobes and stamens; H. Upper part of flower showing closeup of perianth; I. Outer perianth lobes; J. Inner perianth lobes; K. Stamen, see the two lateral thecae, apical crests and basal spur; L. Gynoecium; M. Enlarged view of stigma; N. Seeds; O. Cross section of ovary. (A–M from Santhosh Nampy 170085; O from Dani Francis & Vishnu Mohan 164619).

FIGURE 3. Type of Burmannia indica Jonker.

FIGURE 4. Map showing the distribution of Burmannia munnarensis Dani & Nampy and B. indica Jonker.