Crotalaria meeboldii Dunn, Misc. Inform. Kew 1912

Baro, Daimalu, Bawri, Amal & Borthakur, Sachindra Kumar, 2019, Rediscovery of Crotalaria meeboldii (Fabaceae), a threatened species after more than a century, Rheedea 29 (4), pp. 310-313 : 311

Crotalaria meeboldii Dunn, Misc. Inform. Kew 1912 (7): 340. 1912. Lectotype: INDIA, Shibong , Naga hills, 900 m., 12.1907, A. Meebold 7548 (K000591062 digital image!) Fig. 1

Perennial suffruticose, erect herbs, c. 1.5 m tall. Stems terete, branched, hirsute, hairs dense on the younger branches. Leaves simple, alternate; petioles c. 0.1 cm long; lamina linear to lanceolate, 8.0–8.5 × 0.3–0.5 cm, acute or obtuse at base, acute at apex, margins entire and ciliate, revolute, abaxially silky pubescent, adaxially glabrous; stipules linear, c. 0.4 cm long, deciduous. Racemes terminal, 8–15 cm long, few to many-flowered or flowers solitary in upper axils; bracts 1, linear-lanceolate, 4–5 mm long, densely white silky pubescent; pedicels c. 2 mm long; bracteoles 2, linear, inserted on the pedicel, 3–4 mm long, covered with white silky pubescence. Calyx bilabiate, 1–1.2 cm long with conspicuously long white silky pubescence, lobes linear-lanceolate, parted half of the length, upper lip consisting of two sepals and lower lip of three sepals, c. 8 mm long, connate at base, acute at apex. Corolla blue to purplish blue, light yellow at base, slightly exserted from the calyx or equal; vexillum obovate-elliptic, 7–8 × 4–6 mm; wing petals paired, c. 8 × 3 mm, multi-veined; keel petals angled. Stamens monadelphous; filaments 1.3–3 mm long, free; anthers dimorphic, basifixed, shorter, c. 1.3 mm long, dorsifixed, longer, c. 3 mm long. Ovary sessile, linear, c. 2.5 mm long; style c. 4.2 mm long, sub-geniculate, covered with trichomes; stigma brush type and contracted, c. 0.3 mm long. Pods brown, oblanceolate, c. 1.2 × 0.6 cm, with short beak and persistent style. Seeds light brown, 1.5–2.0 × 0.6–1.0 mm.

Flowering & fruiting: May–September. Habitat: In grasslands along with Osbeckia nepalensis Hook.f. , Melastoma malabathricum L., Uraria picta (Jacq.) Desv. , Leea aequata L., Narenga porphyrocoma (Hance) Bor , Cymbopogon flexuosus (Nees ex Steud.) W.Watson and Themeda arundinacea (Roxb.) A.Camus.

Distribution: Endemic to India.

Specimen examined: Assam, Manas National Park, Bhuyanpara range, 26̊47’299"N, 91̊ 09’97"E, 150 m, 10.6.2017, D. Baro 4841 ( CAL) .

Conservation status: Crotalaria meeboldii is neither listed in the Red Data Book of Indian Plants ( Nayar & Sastry, 1987 -90) nor in the IUCN Red List ( IUCN, 2019) but mentioned as threatened ( Ansari, 2008).

The population of this species has been found surviving at a critical status with only a few individuals (<100 mature individuals) in grassland. Because of the grassland habitat, the site faces several anthropogenic pressures, e.g. grazing and prescribed fire for grassland management. Such human activities may completely wipe out the existing population. The extent of occurrence of the species is only less than 100 km 2. In the last three years, we observed a steady decline in the quality and territory size of the habitat. Accordingly the species is evaluated as Critically Endangered, as per IUCN Criteria B1ab(iii) and B2ab(iii) ( IUCN 2012).

Notes: In the protologue, the inflorescence is described as up to 50 cm long. But critical observation of fresh specimens and consultation of image of type specimen revealed that it is only up to 15 cm long.

Figures

Fig. 1. CrOtalariaMeebOldii DUnn:aa.. Habit;bb.. LeaVeS;CC.. A POrtiOn OF SteM; d. FlOwer;ee.. BraCteOleS;FF.. BraCt;gg.. CalYX;hh.. Standard Petal; ii i. Wing PetalS; jjj. Keel Petal; k. FlOwerS with PetalS reMOVed;ll l.AndrOeCiUM; M. PiStil; n. POd.