Taxonomic Treatment
Fimbristylis pachmarhiensis Mujaffar, A.P. Tiwari &
R.L.S. Sikarwar sp. nov. (Fig 1 & 2)
Diagnosis: Fimbristylis pachmarhiensis, is closely
similar to F. aestivalis (Retz.) Vahl, by the hairy nature of the
plant but differs from it in having few, slender culms (vs. densely
tufted culms), inflorescence simple to compound, very loose, bearing
10–20 spikelets (vs. inflorescence decompounds corymb, loose, bearing
numerous spikelets), spikelets terete, 8-14-flowered (vs. angular, to
40-flowered spikelets), glume distichous or lower 2 or 3 spiral,
3-nerved (vs. all glume spiral, nerveless), style triquetrous, pubescent
throughout (vs. style flat, ciliate towards the top) and achenes
obovate, 3.0–5.0 × 2.5–3.0 mm, sparsely tuberculate, apex depressed
(vs. achene obovate-elliptic, 0.5–0.8 × 0.2–0.3 mm, brownish, smooth,
apex rounded). The new species also shows resemblance with F.
griffithii Boeckeler in its eligulate leaf and biconvexed achenes.
However, it is quite distinct in having hairy nature of plant (vs.
glabrous nature of plant), inflorescence simple to compound, very loose,
4–6 cm long, bearing 10–20 spikelets (vs. inflorescence decompounds
corymb, loose, 4–10 long, bearing 70–90 spikelets), spikelets terete,
8-14-flowered (vs. spikelets angular, 6–19-flowered), glume distichous
or lower 2 or 3 spiral, 3-nerved (vs. all glume spiral, nerveless),
style triquetrous, pubescent throughout (vs. flat, glabrous throughout)
and achenes sparsely tuberculate, depressed at apex (vs. smooth, rounded
at apex).
Type: India, Madhya Pradesh: Hoshangabad district, Pachmarhi
Biosphere Resereve, Panarpani area (22°25’24.”N; 77° 22’ 56”E), 750 m,
17 November 2015, Mujaffar & Tiwari 2514 (holotype CAL!,
isotypes BSA!).
Description: Annual herb, 10–25 cm tall, with fibrous roots.
Culms slender, trigonous, glabrous or pubscent at the top. Leaves mostly
basal, shorter than culm; sheath brown, 1–4 cm long, pubescent,
obliquely truncate at apex; ligule absent; leaf blade 10–20 cm long,
0.5–0.7 mm wide, pubescent on both surfaces, margin sometimes slightly
involute. Inflorescence simple to compound, large, 4–6 × 2–5 cm,
loosely, bearing 10–20 spikelets; involucral bracts 2–5, foliar, 10 cm
long, lowest 2-3 leafy, shorter than inflorescence, brownish, pubescent;
rays 3–8, primary rays, slender, pubescent, filiform. Spikelets
solitary, terete, oblong, elliptic to lanceolate, 3-4 × 0.5–1.0 mm,
acute at apex, yellow to brownish, 8-14-flowered; rhachilla narrowed,
winged, brownish. Glumes membranous, distichous or lower 2 or 3 spiral,
oblong-ovate, 1.5–2 × 1–1.3 mm, acute at apex, glabrous (lower 2 or 3
puberulent), keeled with the prominent midvein excurrent into a mucro,
3-nerved, hyaline towards margins. Stamen 1 or 2; anther oblong-linear,
0.3-0.4 mm long, brownish, apiculate, spurred at base; filament 1-1.2 mm
long, hyaline. Style slender, triquetrous, pubescent throughout, dilated
at base 0.8–1 mm long; stigma 2, hairy, shorter than style, exserted,c . 0.5 mm long, recurved. Achenes whitish or brownish, biconvex,
obovate, 0.8–1 × 0.5–0.6 mm, narrowed towards base with shortly
stipitate, depressed at apex, apiculate, sparsely tuberculate, shining,
surfaces of achenes reticulate, hexagonal or elliptic to rectangular
epidermal cells.
Etymology: The specific name of this species is derived from
its type locality, which is the Pachmarhi Hills situated in the state of
Madhya Pradesh, India.
Phenology: The phenological period for this species occurs
between September and November.
Habitat and Associated species: This species is found in
forests on rocky areas at elevations ranging from 528 to 609 m. It grows
alongside associated species such as Bulbostylis barbata (Rottb.)
C.B. Clarke, Cyperus castaneus Willd., Cyanotis
fasciculata (B.Heyne ex Roth) Schult. & Schult.f., and Oropetium
thomaeum (L.f.) Trin.
Distribution: This species is known only from a single locality
of Pachmarhi Biosphere Resereve, Hoshangabad district in Madhya Pradesh
(Central India).
Conservation status : Based on the available information, this
plant has been tentatively classified as Data Deficient (DD) in
accordance with the IUCN Red List Categories and criteria (IUCN, 2017).
The existing data is insufficient to evaluate the risk factor associated
with this species. Currently, the plant is known solely from its type
locality. To comprehensively assess its distribution, population
numbers, subpopulation numbers, the count of mature individuals across
its entire range, and the percentage of population decline in recent
years, further investigations are required in similar habitats adjacent
to the known areas.
Taxonomic note : Fimbristylis pachmarhiensis closely
resembles F. aestivalis (Retz.) Vahl due to its hairy
characteristics. However, there are several distinguishing
characteristics that set it apart. Firstly, F. pachmarhiensis has
fewer slender culms compared to F. aestivalis , which has densely
tufted culms. The inflorescence of F. pachmarhiensis is simple to
compound and very loose, bearing 10-20 spikelets, whereas F.
aestivalis has decompound corymbs that are loose and bear numerous
spikelets. In terms of spikelet morphology, F. pachmarhiensis has
terete spikelets with 8-14 flowers, while F. aestivalis has
angular spikelets with up to 40 flowers. Another distinguishing feature
is the arrangement of the glumes: F. pachmarhiensis has glumes that are
distichous or the lower 2 or 3 are spiral and 3-nerved, while in F.
aestivalis, all the glumes are spiral and nerveless. The style ofF. pachmarhiensis is triquetrous and pubescent throughout, while
F. aestivalis has a flat style that is ciliate towards the top.
Additionally, the achenes of F. pachmarhiensis are obovate,
measuring 3.0–5.0 × 2.5–3.0 mm, sparsely tuberculate, and have a
depressed apex. In contrast, F. aestivalis has obovate-elliptic
achenes that are much smaller, measuring 0.5–0.8 × 0.2–0.3 mm.F. aestivalis achenes are brownish, smooth, and have a rounded
apex.
While F. pachmarhiensis shares some similarities with F.
griffithii Boeckeler, such as the eligulate leaf and biconvexed
achenes, there are distinct differences as well. F.
pachmarhiensis exhibits a hairy nature, while F. griffithii is
glabrous. Additionally, the inflorescence of F. pachmarhiensis is
simple to compound, very loose, and measures 4–6 cm in length, bearing
10–20 spikelets. On the other hand, F. griffithii has a
decompound corymb inflorescence that is loose and measures 4–10 cm,
bearing 70–90 spikelets. The spikelets of F. pachmarhiensis are
terete and 8-14-flowered, while those of F. griffithii are
angular and 6–19-flowered. Furthermore, F. pachmarhiensis has
distichous or lower 2 or 3 spiral, 3-nerved glumes, a triquetrous and
pubescent style throughout, and sparsely tuberculate achenes with a
depressed apex. In contrast, F. griffithii has all glumes spiral
and nerveless, a flat style that is glabrous throughout, and achenes
that are smooth and rounded at the apex.
Table 1 The key diagnostic characteristics to distinguishingFimbristylis aestivalis , F. pachmarhiensis , andF. griffithii .