Fimbristylis clarkei Anant Kumar, Halder & Venu

Kumar, A., Halder, S., Ranjan, V. et al. 2013. Fimbristylis clarkei, a new species of Cyperaceae from India. Kew Bulletin 68: 669. https://doi.org/10.1007/s12225-013-9473-x

Morphology Reproductive morphology Inflorescences

Primary rays quadrangular, up to 8 cm long, glabrous; faces flat, sulcate; secondary rays absent; peduncles with one or two spikelets, when in twos, one stalked and the other sessile; spikelets faintly angular, brownish, many-flowered; rachilla narrowly winged; wing triangular Inflorescence compound and spreading, 3 – 6 × 1.5 – 4 cm, anthelate, with 11 – 22 spikelets; involucral bracts 4, foliaceous, shorter than inflorescence, 0.5 – 1.5 cm, alternately ridged and grooved, broader at base, smooth at margin, tapering above, sparsely hairy

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes spirally arranged, clasping the rachilla when young, membranous, elliptic-ovate, 2 × 1 mm, 3-nerved, acute at apex, glabrous, falling off acropetally

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 2; anthers oblong, 0.75 – 0.76 mm long, yellow, dehiscing by longitudinal slits; filaments 0.3 – 0.4 mm long, often persisting and growing up to 1 cm in fruit

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary oblong, minutely stipitate, glabrous, brownish; style dilated at base, c- 0.67 mm long, glabrous; stigmas 2, c- 0.7 mm long, nodulose; nutlets biconvex, obovoid, 0.8 × 0.7 mm, shortly-stipitate, creamy-yellowish to brownish, scrobiculate (marked with many shallow depressions), not terminated by an umbo

Distribution

India, West Bengal, Jalpaiguri.

Type

Type: India, West Bengal, Buxa Wildlife Sanctuary, Marakata 81 m, (26°35'40.37""N, 89°45'55.27""E), 24 Sept. 2011 Anant Kumar 52881 (holotype CAL, isotype ASSAM).

Morphology General Habit

Perennial with very short rhizome and fibrous roots, 18 – 70 cm high

Morphology Stem

Stems slender, 1 mm thick, 4 or 5-angled, sulcate, tufted, 15 – 65 cm high, glabrous

Morphology Leaves

Leaves slender and flat, half as long as stem, 1 – 2.5 mm thick, multi-canaliculate, glabrous; margins entire and involute; ligule absent; leaf sheath 5 – 7 cm long, clasping stem entirely below, obliquely truncate above, reddish brown at margin, glabrous

Ecology

Usually on the banks of rivers/rivulets in marshy areas and among common weeds including grasses in plains to c. 100 m.

Conservation

Fimbristylis clarkei was collected from the Buxa Wildlife Sanctuary, in two localities, at least 5 – 6 individuals in each location and also from the Gorumara National Park, near Tower road with 3 – 5 individuals. All three locations from which this new species is reported fall under the protected area network. There is no data on whether the rhizome is eaten by rodents or other wild animals.

Phenology

Fruiting in September – December

Note

Nutlet surface features, photographed through Nikon SMZ1500, add additional distinctions not only to the new species but to the earlier, confused species. In Fimbristylislimosa (Fig. 2D), the nutlet is much smaller with 3 – 4 sucker-like structures of variable size on either side which in turn have projections; in F. dichotoma (Fig. 2E & F) the reticulation is in three distinct rows with clear trabeculae; in F. griffithii (Fig. 2B) the reticulation is transversely elliptic, not impressed epidermal cells; F. clarkei (Fig. 2A) is rough and densely pitted and in F. aestivalis (Fig. 2C), the nut is smooth with distinct margins and no reticulation. Similar to Fimbristylis griffithii Boeckeler but differs from it in being perennial with very a short rhizome; spikelets pedunculate or sessile and giving an anthelate appearance; glumes elliptic-ovate, acute; style bases dilated and nutlets rough with pits, scrobiculate and not terminated by an umbo. The specific epithet of the new species is given in honour of C. B. Clarke who wrote up Cyperaceae for Flora of British India.