Agrostis griffithiana (Hooker) Bor (1960: 387)

Paszko, Beata & Pendry, Colin A., 2013, Agrostis griffithiana (Poaceae: Agrostidinae) - typification, a new synonym and an update of the distribution in India, Phytotaxa 140 (1), pp. 26-34 : 27-31

Agrostis griffithiana (Hooker) Bor (1960: 387) ( Figs 1–3 ).

Basionym:— Calamagrostis griffithiana Hooker (1896: 263) .

Type:— INDIA. [Meghalaya]: Khasia [Khasi Hills], Boga Panee [Boga-panee], ‘ Agrostis hookeriana var. aspera Munro’ , 27 October 1850, Hooker & Thomson s.n. (lectotype here designated K000032345 !; isolectotypes CAL0000002382 !, K000032344 !, L0043527 !, LE!, W1916-0036491 !, W!) .

Other syntype material of Agrostis griffithiana (labelled as ‘ Lachnagrostis griffithii , Munro’):— NE INDIA. [Meghalaya]: Khasia, Moflong, Griffith s.n. ( K!, two sheets).

Excluded syntypes (specimens of Deyeuxia griffithii cited by Hooker (1896) under Calamagrostis griffithiana ):— NE INDIA. [Meghalaya: Khasia Hills], Griffith 6598 ( K!, CAL 0000002383!, W 0026809!, LE!).

Excluded syntypes (specimens of Agrostis pilosula cited by Hooker (1896) under Calamagrostis griffithiana ):—NW INDIA. [Uttarakhand]: Kumaon, Almora, ‘ Agrostis royleana Munro’, 1676.4 m, Strachey & Winterbottom 2 ( BM 000959403!).

Agrostis wardii Bor (1949: 444) . Type:— INDIA. Manipur: Sirhoi Kashong , 2438 m, 8 October 1948, Kingdon-Ward 18145 (holotype K000032328 !; isotype BM000959405 ), syn. nov.

Amended description: — Annual(?), single shoots(?). Culms 60–90 cm tall, unbranched, slender, erect, smooth, nodes 4–7. Sheaths smooth or subscaberulous, collars glabrous; ligule blunt 0.6–3 mm long. Cauline blades 10–23 cm long, 2.7–8.5 mm wide, flat, adaxial surface with moderate ribs, with intercostal valleys, ribs slightly scabrous, green, abaxial surface scabrous. Panicle 9 − 24 cm long, side branches 4–10 cm, in whorls of 2–6, branching in upper half, with secondary and tertiary branchlets. Spikelets 1-flowered, pedicels 0.5–1.2 times length of lower glume; glumes subequal or equal, frequently hispid on keel, apices subacute, lower glume 3.15–4.15 mm long, 0.85–1.07 mm wide, 1-veined, upper glume 2.9–3.5 mm long, 0.70–0.95 mm wide, 1-veined, 0.83–0.99 times length of lower glume; callus shortly hairy, hairs in two small tufts on ventral side, 0.3–0.5 mm, 0.13–0.23 times length of lemma; lemma 2.0– 2.4 mm, hairy all over except area below tip, 5-veined, 0.53–0.70 times length of lower glume, tip truncate with 2(–4) short bristles, lateral longest, awn well developed, 4.8–5.6 mm, geniculate, inserted just above base, exerted from glumes; palea 1.50–1.85 mm, 0.65–0.93 times length of lemma; rachilla extensions absent; anthers 0.75–0.94 mm.

Distribution: — India, Meghalaya (part of Assam prior to 1970) at an elevation of 1350–1850 m and eastern Manipur at an elevation of about 2440 m. There are few herbarium collections of A. griffithiana and it is poorly known across its range. Although it has also been reported from Kumaon, NW India ( Hooker 1896), Arunachal Pradesh and Nagaland, NE India ( Shukla 1996), Himachal Pradesh (NW India), Uttar Pradesh [N India], Nagaland (NE India) ( Moulik 1997), we have not been able to trace specimens from these regions.

Ecology: — Little is known about the ecology of this species. In East Manipur it was collected on open, grassy slopes which are burnt annually.

An account of original material and notes on syntypes: — In the protologue of Calamagrostis griffithiana there are references to four names: ‘ Calamagrostis hookeriana var. aspera Munro’, ‘ Agrostis royleana Munro’, ‘ Lachnagrostis griffithiana Munro’, and ‘ Deyeuxia griffithii Munro’. In addition, Hooker (1896) cited the following collections: Strachey & Winterbottom, from Kumaon at an elevation 5000 ft, Griffith (Kew distr. no. 6598) and Hooker & Thompson from Khasia Hills (currently Khasi Hills which are part of the Garo-Khasi range in the Indian state of Meghalaya, and are part of the Patkai range and of the Meghalaya subtropical forests ecoregion).

The search for syntypes of Calamagrostis griffithiana revealed fourteen collections which can be treated as original material at six different herbaria: BM, CAL, K, L, LE and W. However, these collections actually comprise three species: Agrostis griffithiana (nine collections), Deyeuxia griffithii (four collections) and Agrostis pilosula (one collection). This study found that Hooker’s description of Calamagrostis griffithiana matches two syntype series, mentioned in the protologue, both collected from the Khasi Hills: ‘ Agrostis hookeriana var. aspera Munro’ (seven herbarium sheets), and ‘ Lachnagrostis griffithii , Munro’ (two herbarium sheets).

Bor (1970) noted that Griffith’s collection no. 6598 is not a good match with Agrostis griffithiana . Therefore, based on a collection housed at Kew, he described a new species of Deyeuxia , namely D. griffithii ( Bor 1970: 272) , endemic to Afghanistan. It is difficult to understand why Bor (1970) referred Griffith’s collection to Afghanistan, when Hooker (1896: 263) had previously cited it from Khasia Hills (Meghalaya, NE India). We have traced four syntypes which bear this name, but their herbarium labels bear no information about precise location and date of collection. Until now, the species has been known only from the type collection. Morphologically Deyeuxia griffithii is characterized by glabrous lemmas and the absence of short bristles on lemma tip. The current analysis reveals that in morphology, Deyeuxia griffithii shows similarity to the polymorphic D. scabrescens ( Grisebach 1868: 79) Munro ex Duthie ( Atkinson 1882: 628) , and therefore its relationship with this group should be further examined.

Our morphological investigations show that the syntype, Strachey & Winterbottom no. 2, collected from Kumaon in northwestern India, represents Agrostis pilosula .

Typification: — Moulik (1997: 370) indicated unspecified material in CAL as the type of Calamagrostis griffithiana but two sheets are annotated with this name (Hooker & Thomson s.n., CAL0000002382!; Griffith 6598, CAL0000002383!). As they are evidently not a single gathering and represent two different species (Art. 9.17, McNeill et al. 2012), it was not an effective choice.

One of the four K sheets of Calamagrostis griffithiana (K000032345!) has Hooker’s identification and all the information needed to confirm it as the lectotype of C. griffithiana . On its herbarium label and field label there is information about precise locality (Boga Panee), date of collection (27 October 1850), collector names (Hooker & Thomson), and the identification ‘ Agrostis hookeriana var. aspera ’ made by Munro. Moreover, there are also sketches of the spikelets, probably made by Hooker (or possibly Stapf), which show the defining characters of C. griffithiana .

Taxonomic remarks: — Much of the information in Hooker’s (1896) diagnosis and description is very clear, leaving no confusion about the identity of Calamagrostis griffithiana . The most unambiguous statements in the protologue are: lemma hairy all over; lemma tip truncate with 4 short bristles, the lateral longest; palea nearly as long as its glume [lemma] and hairs of callus very short. Information about the awn insertion on the back of the lemma and panicle branches is less clear, since according to Hooker C. griffithiana is characterized by the ‘awn subbasal to median exerted’ and ‘branches 2–5-nate’, whereas our revision shows that the awn is inserted in the lower quarter of the back of the lemma and side branches usually bear secondary and tertiary branchlets.

New synonym: — Agrostis wardii Bor (1949: 444) was considered by its author to be allied to A. stolonifera Linnaeus (1753: 62) . He pointed out that it can be distinguished by a 4-aristulate lemma tip and geniculate lemma awn inserted just above the base. Examination of the holotype of Agrostis wardii by the first author has shown that the plant in question has, among other characters, its lemma surface covered with hairs. While this observation agrees with the original description, Bor (1949) did not mention this character as diagnostic for his new species. In the protologue of A. wardii , the lemma is described by Bor (1949) as: “ Lemma hyalinum, tenuiter membranaceum, 2–2.5 mm longum, explanatum oblongo-ovatum, apice truncatum, brevissime 4-fidum, dorso praecipue prope margines pilosum, 5-nerve ” (i.e. “Lemma hyaline, finely membranous, 2–2.5 mm long, in a flattened-out state oblong-ovate, apex truncate, shortly 4-aristulate, lemma surface specially close to edges hairy, 5-veined”). Analysis of other morphological characters has not revealed any significant differences between A. wardii and A. griffithiana . In conclusion, we consider A. wardii to be a new synonym of A. griffithiana .

Bor’s (1960) identification key to Agrostis placed Agrostis wardii in a group of species distinguished by glabrous, awned lemmas. This group also includes A. triaristata (Hook. f.) Bor, non Knapp (1804: 23) (= Calamagrostis filiformis Grisebach (1868: 79)) , A. peninsularis Hooker (1896: 255) , A. debilis ( Hooker 1896: 262) Bor (1960: 387) , non Poiret (1810: 249) (= Deyeuxia debilis (Hook. f.) Veldkamp in Korthof & Veldkamp (1984: 220)), and other species. Meanwhile Agrostis griffithiana was grouped by Bor (1960) among species of Agrostis characterized by awned, hairy lemmas, including A. munroana , A. pilosula , and A. burmanica . It is hard to understand why Bor (1960) linked Agrostis wardii with species which are characterized by glabrous lemmas.

Similar species: — Agrostis griffithiana is morphologically similar to A. pilosula and A. munroana with all three species having hairy lemmas. Agrostis griffithiana differs from A. pilosula by having a longer paleas (1.50–1.85 vs. 0.35–1 mm) and the higher ratio of palea length to lemma length (0.65–0.93 vs. 0.18–0.55) ( Fig. 4 ). Agrostis griffithiana differs from A. munroana by having a longer lemma awn length (4.8–5.6 vs. 0.35–1.75 mm), longer lemmas (2.0–2.4 vs. 15–2.35), longer lower glumes (3.15–4.15 vs. 1.80–2.95 mm) and longer upper glumes (2.9–3.5 vs. 2–3 mm). The two best characters to separate these three species are lemma awn length and the ratio of palea length to lemma length ( Fig. 4 ).

Figures

FIGURE 1. Lectotype of Calamagrostis griffithiana, Hooker & Thomson s.n. (K). With permission from the Board of the Trustees of RBG, Kew.

FIGURE 2. Holotype of Agrostis wardii (= A. griffithiana), Kingdon-Ward 18145 (K). With permission from the Board of the Trustees of RBG, Kew.

FIGURE 3. Agrostis griffithiana. A. spikelet; B. glumes and separated floret; C. hairy lemma in dorsal view with awn inserted just above the base; D. anthers; E. ligule and the junction between the leaf sheath and the leaf blade; F. upper leaf surface. A–E from Hooker & Thomson s.n. (W1916-0036491), F from Kingdon-Ward 18145 (K). Scale bar: A, B, E = 1 mm; C, D, F = 0.5 mm.

FIGURE 4. Scatter plot of two characters: lemma awn length against the ratio of palea length to lemma length, for Agrostis griffithiana (solid triangles), A. pilosula (solid circles) and A. munroana (open squares). Abbreviations: 1, Agrostis wardii—holotype; 2, Calamagrostis griffithiana—lectotype.