Dimeria ornithopoda var. gracillima, Bor, 1953

Teerawatananon, Atchara, Boontia, Veeraya, Chantarasuwan, Bhanumas, Hodkinson, Trevor R. & Sungkaew, Sarawood, 2014, A taxonomic revision of the genus Dimeria (Poaceae: Panicoideae) in Thailand, Phytotaxa 186 (3), pp. 137-147 : 142-145

- Spikelets 1–1.5 mm long; anthers up to 0.25 mm long................................................................................................ var. gracillima var. ornithopoda

Annual, tufted. Culms slender, (4–) 20–50 cm tall, erect or ascending, branched; nodes pubescent. Leaf-sheaths 1–4 cm long, margins scarious, glabrous to pilose with tubercle-based hairs. Ligule (0.3–) 0.5 mm long. Leaf-blades linearlanceolate, 2–5 × 1–3 mm, glabrous to hirsute or pilose with tubercle-based hairs on both surfaces, margins pilose with tubercle-based hair, scabrous near the apex. Racemes 2–3(–4), 1–6(–8) cm long, rhachis triangular, 0.2–0.4(–0.5) mm wide, narrowly winged or wingless, margins scabrous, rhachis internodes 0.5–1(–1.5) mm long; pedicels ca. 0.1 mm long, flattened, concave above. Spikelets linear-oblong or elliptic-oblong, 1.5–3(–4.5) × 1–1.2 mm; lower glumes linear-oblong, 0.8–3 mm long, more or less shortly hairy at both sides, acute, scabrous on keel; upper glumes oblongelliptic, 1–3.5 mm long, scabrous and ciliate on the dorsal surface, strongly compressed, but not keeled, more or less shortly hairy on the sides, acuminate, wingless, sometimes upper glumes of basal spikelets narrowly winged; lower lemmas 0.5–1.5 mm long; upper lemmas 0.8–2 mm long, awns (3–)4–5(–12) mm long, columns 1.5–2.5(–3.5) mm long; anthers, 0.25–0.5 mm long; stigmas 0.3–0.6 mm long. Caryopsis 1–1.5 mm long. Figs. 1H & 2C–D .

Distribution: — India, Nepal, Bangladesh, Myanmar, China, Vietnam, Malaysia, Singapore, Indonesia (Java), Philippines and Australia, Thailand (Eastern: Ubon Ratchathani, Si Sa Ket; South-Western: Kanchanaburi; Central: Nakhon Nayok; South-Eastern: Chanthaburi; Trat; Peninsular: Chumphon, Phangnga, Ranong, Satun, Songkhla, Surat Thani, Trang.

Ecology: —Open grassy areas, secondary grasslands, wet sandy soil areas, rice fields, seasonally flooded flatlands, hill slopes, on rocks by the sea, along stream banks, secondary forests. 0–700 m elevation.

Notes: —This is a widespread and variable species, showing much variation in its height, the hairiness of vegetative parts and spikelets, and the length of racemes. In Thailand, two varieties are recognised based on the length of their spikelets and stamens. The specimens of Laegaard et al. (No. 21840) in BKF and Kerr (No. 9446) have 2 to 4 racemes.

The specimens examined from Thailand have been found to have slightly longer awns than elsewhere.

Nomenclature notes: —When Trinius (1832) first published D. tenera , he mentioned two specimens collected from Manila (Manill.) and Nepal as the type specimens, but did not mention the collector’s name and number.According to Soreng et al. (1996), most of Trinius’s type specimens are housed in LE. We have found one sheet of D. tenera in LE (Trinius 1255.01, IDC microfiche at K) that contains two specimens and two labels written by Trinius. One of these is labelled as “ D. tenera Trin. , Nepal ”, another was collected by L.A. von Chamisso and labelled as “ D. tenera m, (handwriting on label unreadable), Manilla (handwriting on label unreadable), de Chamisso (without a number), 1821”. It is possible that Trinius (1832) described D. tenera based on these specimens. In addition, we also found that L.A. von Chamisso was a French born German naturalist, who sailed as a botanist on the Russian vessel “ Rurik” on a scientific circumnavigation of the world in 1815 and returned to St. Petersburg in 1818 via Manila. The first set of his collections on the voyage of the Rurik is at LE ( Stafleu & Cowan 1976; Liebersohn 1994). So, it is possible that Trinius’s (1832) type specimen could have been collected by Chamisso. In selecting a lectotype, the Manila specimen has priority as the first specimen cited by Trinius (1832). Therefore, we have selected the specimen of Chamisso (without a number) in LE (Trinius 1255.01, IDC microfiche at K), as the lectotype.

Specimens examined: — AUSTRALIA. Northern Territory: Port Darwin , Schultz 321 ( K) . BANGLADESH. Bengal ( East Bengal ): Griffith s.n. ( K) . INDIA. Karnataka: Mangalore , 1847, Hohenacker 231 ( BM, K, TCD) . Meghalaya: Sohra ( Cherra ), 4,000 ft, 6 Oct. 1867, Clarke 5624 ( K) . INDONESIA. Java: Tjikoya , 27 July 1842, Zollinger 351 ( BM) ; 1802, Horsfield 135 ( BM) ; Lobb 135 ( BM, TCD) . MALAYSIA. Kedah: Langkawi , Feb. 189?, Ridley 15508 ( BM) . Sabah: Sadankan , 1920, Ramos 1301 ( K) . MYANMAR. Bago (Pegu): Taungoo ( Toungoo ), 31 Oct. 1947, U Thein Lwin 301 ( K) ; Kurz 2727 ( K) ; Dec. U Thein Lwin 2926 ( K) . Tenasserim: Helfer s.n. ( K) ; Helfer s.n. (2 sheets K) . Yangoon (Rangoon): Mingaladon , 20 Oct. 1948, U Thein Lwin 656 ( K) . NEPAL. No locality: 1821, Wallich 8841 ( TCD) ; Wallich s.n. ( K) . PHILIPPINES. Luzon : Rizal, 4 Dec. 1910, Merrill 781 ( BM) . Palawan: Culion , Oct. 1922, Ramos 41312 ( BM) . SINGAPORE. No locality: 29 Dec. 1989, Ridley 1703 ( BM) . VIETNAM. Nha Trang : Mar. 1911, Robinson 1265 ( BM) ]. No locality: Pierre s.n. ( BM) . THAILAND. Ubon Ratchathani: Khong Chiam , 150 m, 27 Oct. 2001, Laegaard et al. 21840 ( AAU, BKF, K, US) ; Khong Chiam , 11 Nov. 2006, Teerawatananon & Kritsanachandee 965 ( BKF, Natural History Museum, Thailand ) ; Kaeng Tana , 11 Nov. 2006, Teerawatananon & Kritsanachandee 967 ( BKF, Natural History Museum , Thailand ) ; Pha Tan , 215 m, 28 Oct. 2001, Laegaard et al. 21859 ( AAU) ; Warin Chamrap , 125 m, 27 Oct. 2001, Laegaard et al. 21813 ( AAU) . Si Sa Ket: Kantaralak, Khao Phra Vihan National Park , 400 m, 21 Dec. 2005, Pooma et al. 6059 ( BKF) . Kanchanaburi: Thong Phaphum , 450 m, 23 Oct. 2004, Sirimongkol 163 (2 sheets BKF) ; Thong Phaphum , 3 Nov. 2005, Teerawatananon & Sungkaew 666 ( BKF, Natural History Museum, Thailand) ; Thong Phaphum , 3 Nov. 2005, Teerawatananon & Sungkaew 667 ( BKF, Natural History Museum, Thailand) . Nakhon Nayok: Khao Yai , 750 m, 17 Dec. 2001, Maxwell 01-726 ( GH) . Chanthaburi: Northwest of Chanthaburi , 25 Nov. 1970, Lazarides 7466 ( C, K, L) ; North of Chanthaburi , 25 Nov. 1970, Lazarides 7473 ( C, K, L) ; Laem Sing , ca. 50 m, 23 Nov. 1924, Kerr 9374 ( BK, BM, K) ; Trat: Khao Saming , ca. 20 m, 27 Nov. 1924, Kerr 9446 ( BK, BM, K) ; Ko Chang, Lem Dan Kao , ca. 500 m, 3 Oct. 1924, Kerr 9317 ( BK, BM, K) ; Ko Chang , 8 Nov. 2005, Teerawatananon & Sungkaew 685 ( BKF, Natural History Museum, Thailand) . Chumphon: Bang Son , 20 m, 9 May 1927, Kerr 11312 ( ABD, BK, 2 sheets K) ; Muang , 5 m, 15 Jan. 1987, Maxwell 87-41 ( AAU, BKF, GH, L) . Phangnga: Nop Pring , ca. 100 m, 6 Mar. 1930, Kerr 18397 ( BK) . Satun: Tarutao , 5 m, 27 Feb. 1966, Hansen & Smitinand 12454 ( BKF, C, K, L) ]; Tarutao , 13 Jan. 1981, Congdon 1062 ( AAU, GH) ; ca. 5 m, 28 Dec. 1927, Kerr 13720 ( BK, BM, 3 sheets K) . Songkhla: Na Mom , 50 m, 9 Apr. 1986, Maxwell 86-230 ( BKF, GH, L) ; Surin , ca. 200 m, 13 Jan. 1924, Kerr 8275 ( BK, BM, K, TCD) . Surat Thani: Tha Chang , 5 Feb. 1987, Maxwell 87-162 ( BKF, GH, 2 sheets L) ; ca. 10 m, 6 Jan. 1927, Kerr 11293 ( ABD, BK, BM, 3 sheets K) . Trang: Khao Chong ( Kachawng ), Feb. 1950, Williams 17250 ( K) .

var. gracillima Bor (1953: 576) . Lectotype (designated here):— INDIA, Jharkhand, Parasnath , 4000 ft, 1 Oct. 1873 Clarke 21084B ( K000245790 !).

Culms up to 35 cm tall. Leaf-sheaths and blades densely pilose with tubercle-based hairs. Ligule a ciliate membrane, 0.3–0.7 mm long. Racemes 2, 1.5–5 cm long. Spikelets elliptic-oblong, 1–1.5 mm long; glumes scabrous along the dorsal surface, ciliate on the sides; anthers ca. 0.25–3 mm long.

Distribution: — India, Thailand (Northern: Chiang Mai).

Ecology: —Open areas or hill slopes in montane forests. 1,500–1,700 m elevation.

Vernacular name: —Ya Khon Mai (from Bunchuai No. 1401)

Notes: —Specimens from Thailand housed in K and L have slightly longer spikelets than those of Clarke (Nos. 21084B, 33719A).

Kiran Raj (2008) mentioned that the length of racemes was 3–5 mm. However, we have examined Clarke’s specimens (Nos. 21084B, 33719A and 33719C) in K and specimens from Thailand and found that their racemes are 1–3.5 cm long.

Nomenclature notes: — Bor (1952) cited three specimens of Clarke (Nos. 21084B, 33719A and 33719C) in K as syntypes of D. ornithopoda var. gracillima . However, in selecting a lectotype, we selected the specimen of Clarke (No. 21084B; K000245790) as the lectotype because it was the first specimen cited by Bor (1952).

Specimens examined: — INDIA. Jharkhand: Parasnath , 4000 ft, 1 Oct. 1873 Clarke 21084 B ( K) ; Parasnath , 4,300 ft, 7 Oct. 1883 Clarke 33719 A ( K) ; Parasnath , 4,300 ft, 7 Oct. 1883 Clarke 33719 C ( K) . THAILAND. Chiang Mai: Chom Thong, Doi Inthanon National Park, Doi Hua Sua , 1,600 m, 17 Dec. 1998, Konta et al. 4645 (3 sheets BKF) ; Doi Buak Ha , ca. 1,575 m, 30 Nov. 1965, Hennipman 3174 ( BKF, C, K, L) ; Doi Inthanon , 22 Nov. 1964, Bunchuai 1401 ( BKF) ; Doi Pui , 1,550 m, 28 Nov. 1961, Smitinand & Anderson 7199 ( BKF, 2 sheets K) ; Doi Suthep , 12 Dec. 1904, Hosseus 212 ( BM, K, L) ; Doi Suthep. , 5,500 ft, 12 Nov. 1911, Kerr 1581 B ( BM, K) ; Doi Suthep , 1,700 m, 6 Dec. 1957, Richards 5462 ( K) ; Doi Suthep , 1,600 m, 11 Dec. 1957, Smitinand 3963 ( BKF, K) ; Inthanon , 1,700 –1,800 m, 18 Dec. 1998, Konta & Khao-iem 11287 ( BKF) .

6. Dimeria sinensis Rendle (1904: 359) . Holotype:— CHINA. Guangdong (Kwangtung), Guangzhou (Canton), Hance 1385 pro parte (BM!; with Kew negative no. 12340).

Annual, caespitose. Culms 10 – 50 cm tall, slender, erect; nodes pubescent. Leaf-sheaths 1 – 4 cm long, pilose with tubercle-based hairs, margins scarious. Ligule ca. 0.5 mm long. Leaf-blades linear, 1.5 – 10 × 0.2 – 0.5 cm, pilose with tubercle-based hairs on both surfaces and hirsute underneath, margins pilose with tubercle-based hairs, scabrous near the apex. Racemes solitary, 2–7 cm long, rhachis 0.4–0.7 mm wide, flattened (slightly ridged or convex on upper surface) to triangular, narrowly winged, margins ciliate, rhachis internodes 0.2–0.8 mm long; pedicels 0.3 – 0.5 mm long, flattened, concave above, margins ciliate. Spikelets ovate-oblong, (2–)3–4 × 1–1.3 mm; lower glumes linear to oblong, 3–4 mm long, acute to obtuse, keeled, densely ciliate on keel and on both sides of the lower half; upper glumes oblong-elliptic, 3.5 – 4 mm long, acute, keeled, densely ciliate on keel and near margins, broadly winged all along the keel; lower lemmas 1.5 – 2 mm long; upper lemmas 2.5–3 mm long, awns 12–18 mm long, columns 3–6 mm long; anthers 1–1.2 mm long; stigmas 0.5–0.7 mm long. Caryopsis 1 – 2.5 mm long. Figs. 1E & 2E–F .

Distribution: — China, Thailand (Northern: Phitsanulok; North-Eastern: Nakhon Phanom, Nong Khai; Eastern: Chaiyaphum, Surin; Central: Bangkok, Nakhon Nayok; South-Eastern: Chanthaburi; Peninsular: Phangnga).

Ecology: —Open grassy areas, seasonally flooded flatlands, rocky mountains, wet sandy soil areas, paddy fields, along the edge of rocky or sandstone areas. 0 – 100 m elevation.

Notes: —Four sheets of Hance’s specimens (No. 1385) were found in this study. Three of them are at BM and another is at K. The BM specimens were collected from Guangzhou (Cantone or Canton) on September 1869, Xiamen (Amoy) on October 1857 and Hong Kong on October 1859, respectively. The first one (from Guangzhou) is the holotype of D. sinensis , while the others are D. falcata . We also found another sheet of Hance (No. 1385) in K (K000433919) that contains two specimens. The specimen on the right hand side was collected from Hong Kong in November 1859, and the left hand side was collected from Amoy. We have examined them and found that they are both D. falcata .

Dimeria sinensis was a new record for Thailand, previously reported by Chen & Phillips (2006).

Dimeria sinensis is similar to D. kurzii , from which it can be distinguished by the winged upper glumes. It is also close to D. fischeri Bor (1952: 564) , but differs from the latter in the following characters: upper lemma awn in D. sinensis is longer (12–18 mm), while D. fischeri is shorter (ca. 10 mm); anther length in D. sinensis is longer (1–1.2 mm), while D. fischeri is shorter (ca. 0.8 mm).

Specimens examined: — CHINA. Guangdong: Guangzhou (Cantone), Sept. 1869, Hance 1835 in part ( BM) .

Hong Kong: High Island , 14 Oct. 1969, Shiu Ying Hu 8251 ( K) ; Leadmine Pass , 2 Nov. 1971, Paul But 275 ( K) . THAILAND . Phitsanulok: Nakhon Thai , 1,100 m, 29 Oct. 2001, Watthana & Suksathan 1546 ( AAU) . Nakhon Phanom: Tha Uthen , 27 Nov. 2005, Teerawatananon & Sungkaew 819 ( BKF, Natural History Museum, Thailand) ; Tha Uthen , 9 Oct. 2006, Teerawatananon & Kritsanachandee 946 ( BKF, Natural History Museum, Thailand) . Nong Khai: Bueng Kan, Huai Poo , 100 m, 17 Nov. 1966, Smitinand 10093 ( K, 2 sheets L) . Chaiyaphum: Chum Pae , 19 Dec. 1929, Kerr 17618 A ( K) . Surin: 100 m, 9 Jan. 1924, Kerr 8235 ( BK, BM, K, TCD) . Bangkok: 21 Nov. 1930, Kerr 19868 ( BK, BM, K) . Nakhon Nayok: 17 Dec. 2001, Maxwell 01-725 ( GH) . Prachin Buri: Kao E-To, 26 Dec. 1966, Jaray & Sakol 2004 ( BK) ; Prachantakham , 25 Dec. 1966, Jaray & Sakol 2050 ( BK) . Chanthaburi: Northwest of Chanthaburi , 25 Nov. 1970, Lazarides 7457 ( C, K, L) ; Makham , ca. 100 m, 18 Jan. 1958, SØrensen et al. 462 ( C, K) ; Makham , 50 m, 22 Dec. 1959, Smitinand 6279 ( BKF, K) . Ranong: Kapoe , 0 m, 29 Nov. 1996, Maxwell 96-1553 (2 sheets GH) .

7. Dimeria velutina (Hackel) Bor (1952: 458) . D. leptorhachis Hackel (1889: 89) subsp. velutina Hackel (1889: 90) . Lectotype (designated here):— MYANMAR, Tenasserim? Griffith 6799 (K000245776!); isolectotypes (K000245777!), E! (2 sheets), digital image MO2151002!.

Perennial, caespitose. Culms up to 80 cm tall, erect; nodes pubescent, stems waxy below the nodes, covered with overlapping sheaths in the lower half. Leaf-sheaths 10–17 cm long, tight, the older breaking away from the culm, striate on the back and sides, densely pilose with tubercle-based hairs. Ligule 1–2 mm long. Leaf-blades linear-lanceolate, up to 20 × 0.7–1.2 cm, pilose to densely pubescent with tubercle-based hairs on both surfaces, margins scabrous. Racemes 4–8, up to 16 cm long, rhachis filiform, straight or slightly zigzagged, glabrous, with a glandular pit at the base, rhachis internodes (2.5–) 4–6 mm long; pedicels clavate, 0.5–1 mm long, glabrous. Spikelets linear-oblong, (4.5–)6–7 × 0.8–1 mm; lower glumes linear-oblong, 4.5–6.5 mm long, ciliate at both sides, acuminate, keeled, scabrous and ciliate on keel; upper glumes oblong-elliptic, 5–6.5 mm long, more or less ciliate on both sides, acuminate, keeled, scabrous and ciliate on keel, wingless; lower lemmas 3–4 mm long; upper lemmas 3.5–5 mm long, awns 8–12 mm long, columns 2.5–4 mm long; anthers ca. 3.5 mm long. Caryopsis not seen. Fig. 1A .

Distribution: — Myanmar and Thailand (South-Eastern: Trat).

Habitat and ecology: —On open sandy grassland. ca. 600 m elevation.

Notes: —The specimen of Kerr (No. 17725) in BK, BM and K was reported as D. leptorhachis (now D. gracilis Nees von Esenbeck ex Steudel (1854: 413) . We have examined these specimens and compared them with the type specimens of D. velutina (Griffith No. 6799) and D. gracilis (Thwaites C.P. Nos. 24 and 3261). We found that the specimens from Thailand are similar to D. velutina , but generally differ from D. gracilis in having longer (4−6 mm) raceme internodes, shorter callus hairs and longer (0.5−1 mm) pedicels.

Nomenclature notes: — When Bor (1952) described D. velutina , two sheets of Griffith (No. 6799) in K were mentioned. We have selected K000245776 as a lectotype because it is the most representative of this species .

Specimens examined: — MYANMAR. Tenasserim: Griffith 6799 (2 sheets E, 2 sheets K, digital image MO5472471 ; Helfer s.n. (2 sheets K). THAILAND. Trat: Khao Kuap , ca. 600 m, 23 Dec. 1929, Kerr 17725 ( BK, BM, 2 sheets K).

Figures

FIGURE 1. Raceme rhachis characteristics of Thai Dimeria species. A. Rhachis filiform (D. velutina). B. Rhachis flattened, slightly ridged or convex (D. fuscescens). C. Rhachis flattened, slightly ridged (D. kerrii). D. Rhachis flattened and convex on the upper surface (D. kurumthotticalana). E. Rhachis flattened, slightly ridged or convex on upper surface (D. sinensis). F–G. Rhachis flattened (D. kurzii). H. Rhachis triangular (D. ornithopoda). Scale bar = 5 mm.

FIGURE 2. Dimeria fuscescens (A–B), A. Habit and habitat on rocky ground, B. Inflorescence showing the arrangement of racemes and flowering spikelets. D. ornithopoda var. ornithopoda (C–D), C. Habitat on rocky ground, D. Inflorescence showing the arrangement of racemes. D. sinensis (E–F), E. Habit and habitat in paddy field, F. Inflorescences. D. kurzii (G) Inflorescences showing flowering spikelets.