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Fig. 3 Leersia hexandra Sw.: (a) habit; (b) inflorescence;
(c) spikelet; (d) lemma; (e) palea; (f) lodicules, stamens,
and pistil. Drawn by M. Norsaengsri.
Grasses Burma, Ceylon, India & Pakistan 599. 1960;
Phan. Mono. Tom. 12: 183. 1980; Fl. Ceylon 8:
295. 1994; Fl. China 22: 184. 2006; Fl. North
America 24: 44. 2007; Fl. Australia 44A: 360. 2009.
Type: Jamaica, Swartz s.n. (holotype S!; isotype
BM!).— Leersia ciliata (Retz.) Roxb., Fl. Ind. 2nd
edn, 2: 207. 1832; Pharus ciliatus Retz., Observ.
Bot. 5: 23. 1789.
Type: India, F.G. Koenig s.n.
(lectotype C!, designated here; isolectotypes BM!,
K!, fragm.).— Asprella australis (R.Br.) Roem. &
Schult., Syst. Veg. 2: 267. 1817; Leersia australis
R.Br., Prodr. 210. 1810. Type: Australia, Keppel
Bay, R. Brown 6170 (holotype BM!; isotypes BM!, K!,
2 sheets).— Leersia mexicana Kunth in H.B.K., Nov.
Gen. et Sp. 1, 195. 1816. Type: phototype taken
from H.B.K. microfiche (K!).
Fig. 1
C,D,
Fig. 3
.
Perennial herb. Culms erect shoot up to 1 m tall,
slender, decumbent, rooting at lower nodes, nodes
pubescent. Leaf sheaths tight, smooth or scabrid,
terete; ligule 1.5–4 mm long, glabrous, apex obtuse;
leaf blades
0.4–1
× 4–20 cm, glabrous or glabrescent
on both surfaces, margins rough. Inflorescence a
panicle, branches slender. Spikelets 3–5 mm long,
narrowly elliptic, elliptic to elliptic-oblong, flat, pale
yellow, yellowish-green or tinged purple. Glumes
absent. Lemma 1–1.3
× 3–5 mm, boat-shaped, with
a subpectinately ciliate keel, margins scaberulous,
awnless. Palea folded, shorter than the lemma, 3-
nerved, with a pectinately ciliate mid-nerve. Anthers
yellow.
Thailand.— NORTHERN: Chiang Mai, 7 Nov.
1910,
Kerr 1537 (BM); Doi Sutep, 18 Nov. 1911,
Kerr 1537B
(BM, K), 9 Nov. 1988, J.F. Maxwell
88-1299
(BKF, L); Doi Chiangdao, 2 Jul. 1958, K.
Bunchuai & C. Phengkhlai 926
(K, L); Mae Tang, 19
Oct. 1958, Th. Sørensen, K. Larsen & B. Hansen 5777
(C, K); MaeJam, 20 Aug. 1985, J.F. Maxwell 85-789
(L); Mae Thaeng, 11 Aug. 1990, J.F. Maxwell 90-
874
(L); Doi Inthanon, 2 Oct. 1971, G. Murata et al
T-15872
(BKF); Mae Klang waterfall, 5 Nov. 1965,
P. Singkhachand 93
(BK); Bo Luang, 1 Feb. 1964, B.
Hansen, G. Seidenfaden & T. Smitinand 11013
(BKF,
C, K), Nov. 1986,
C. Phengklai & T. Smitinand 6137
(AAU, BKF, K); Tak, Hard Palom, 20 Dec. 1961, K.
Larsen 8847
(C); Lamphun, Doi Khun Tan National
Park, 31 Oct. 1994, J.F. Maxwell 94–1169 (BKF, L);
Phitsanulok, Thung Salaeng Luang, 23 Jul. 1966, K.
Larsen, T. Smitinand & E. Warncke 768
(AAU, K), 30
Sep. 1967, T. Shimizu T-11302 (BKF); Kamphaeng
Phet, Muang, 12 Aug. 2012, Sumanon & Traiperm
5
(BKF); Nakhon Sawan, Bung Boraphet, 25 Nov.
1987, Vacharee 812 (BK); NORTH-EASTERN: Sakon
Nakhon, Phu Phan National Park, 11 Mar. 1984, G.
Murata et al s.n.
(BKF); Khon Kaen, Kok Phu Taka,
30 Nov. 2003, C. Jaroenchai 31 (KKU); CENTRAL:
Ang Thong, 28 Dec. 1929, Put 2585 (BM, K), 28
Feb. 1929, Put 2585 (BK); Nakhon Pathom, Mahidol
University, Salaya, 24 Jan. 1999, J.F. Maxwell 99-
24
(L); Bangkok, Pak Kret, 6 Jan. 1914, A. Marcan
1604
(BM), 19 Oct. 1919, Kerr 3827 (BM, C, K),
30 Oct. 1923, Kerr s.n. (BK, BM), 5 Dec. 1926, Kerr
11103
(BK, BM, K); SOUTH-EASTERN: Rayong,
26 Nov. 1970, Lazarides 7943 (K, L); PENINSU-
LAR: Chumphon, Paknam Chumphon, 12 Feb. 1968,
Vacharapong 22
(BK); Surat Thani, Khun Talae Lake,
12 Jan. 1935, G. Seidenfaden 2300 (C); Nakhon
Si Thammarat, Kiriwong, 17 Mar. 1951, Phloenchit
719
(BKF); Trang, Chao Chong, 29 Oct. 1984, J.F.
Maxwell 84-358
(BKF), 12 Nov. 1990, K. Larsen, S.S.
Larsen, A.S. Barfod, W. Nanakorn, W. Ueachirakan &
P. Sirirugsa 41285
(AAU, BKF); Yala, Yaha, Ban Lahm
Lugah, 7 Nov. 1986, J.F. Maxwell 86-877 (BKF, L);
Narathiwat, Su Ngi Paadee, Paa Wai, 10 Feb. 1988,
C. Niyomdham 1660
(AAU, BKF, C, K, L); Toh Daeng,
16 Mar. 1993, P. Chantaranothai, K. Chayamarit, D.
Middleton, J. Parnell & D. Simpson 1192
(K), 4 Aug.
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41 (2015)
1999, C. Niyomdham 5740 (BKF); Tak Bai, 18 Feb.
1984, C. Niyomdham 791 (BKF).
Distribution.— This species is widely distributed
throughout tropical and warm temperate parts of
the world.
Habitat and Ecology.— Growing in sand, clay
or peat on open ground or in partial shade at the
edge of swamps, canals, lakes, and waterholes from
sea level to over 1800 m elevation; often a weed in
paddy fields. Flowering from July until March.
Vernacular name.— Ya-sai.
Uses.— Fodder for livestock.
Conservation status.— This taxon occurs across
a broad elevational range throughout Thailand,
and has an EOO of 619 907 km
2
and an AOO of
168 km
2
.
It was commonly encountered during
our field work, and can colonise a wide variety of
aquatic and moist habitats. We recorded it at 46
locations. Globally, it is extremely widespread and it
is not presently facing any specific threat. We regard
it as LC in Thailand.
Notes.— The Jamaican specimen at S bears
notes written in Swartz’s hand and matches the orig-
inal publication in all details, and should therefore
be considered the holotype.
Retzius’s type of Pharus ciliatus is not to be
found at LD, as might be expected.
Rather, the
Koenig collection of this taxon at C matches the
protologue and, since other Koenig types published
by Anders Jåhan Retzius in his Observationes Botan-
icae are kept in C, we believe this specimen to be a
suitable choice for lectotype of that name.
2.
Leersia stipitata
Bor in Dansk Bot. Ark. 23(2):
147. 1965. Type: Thailand, Chanthaburi, Plain of
Makam, 14 Jun. 1963, K. Larsen 10101 (holotype
C!; isotypes BKF!, K!, fragm.).
Fig. 4
.
Annual herb. Culms slender, terete, glabrous,
nodes hirsute. Leaf sheaths tight, striate, glabres-
cent on both sides, auricles acute; ligule c. 1 mm
long, contracted at base; leaf blades c. 2
× 4 cm,
glabrous.
Inflorescence
racemose, terminal, en-
closed by sheath. Spikelets 5–6 mm long with a
short pedicel c. 1 mm long, hirsute. Glumes ab-
sent. Lemma 4–5 mm long, boat-shaped, keeled, 5-
nerved, hirsute along keel, margins scabrous, apex
tapering to a long, stout, straight awn 7–8.5 mm
long. Palea 5.3–6 mm long, folded, shorter than the
lemma, 2-nerved, scabrous apex. Anthers 1.2 mm
long, yellow. Caryopsis not seen.
Thailand.— Only known from the type collec-
tion.
Distribution.— Endemic to Thailand.
Fig. 4 Leersia stipitata Bor: (a) habit; (b) spikelet. Drawn
by M. Norsaengsri.
Habitat and Ecology.— Growing by a waterhole
at 50 m elevation. Flowering in June.
Conservation assessment.— This species has
only been collected once and is therefore regarded
as having an AOO of just 4 km
2
. As a strict Thai
endemic, it is of global conservation importance. We
revisited the type locality but were unable to find
plants belonging to this taxon. At present, suitable
habitat remains in the vicinity, offering hope that
it may yet be rediscovered. However, the area is
being gradually urbanized, posing a threat to the
persistence of suitable habitat.
Accordingly, we
regard it as being CR (B1
+2ab(ii,iii,iv,v); D).
Oryza
L., Sp. Pl.: 333. 1753; Bor, Grasses Burma, Ceylon,
India & Pakistan 601. 1960; Fl. China 22: 182.
2006. Type species: O. sativa L.— Padia Moritzi,
Syst. Verz.: 103. 1845. Type species: P. meyeriana
Zoll. & Moritzi.
Perennial, rarely annual, tufted or stolonifer-
ous herbs. Culms erect to ascending, sometimes
branching at base. Leaf sheaths loose, not inflated,
with well defined auricles; leaf blades linear to
lanceolate. Inflorescence a panicle. Spikelets not
flattened, bisexual, 1-fertile floret with 2 sterile
lemmas. Glumes cup-shaped; sterile lemma present,
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