Microstegium

Chen, H., Veldkamp, J. - F. & Kuoh, C. - S., 2012, Taxonomic revision of Microstegium s. str. Andropogoneae, Poaceae), Blumea 57 (2), pp. 160-189 : 161

Microstegium

Microstegium Nees (1836) 447; Bor (1952) 209; Sur (1985) 167. — [ Microstegium Nees sect. Eumicrostegium Honda (1930) 403, nom. inval.]. — Pogonatherum P.Beauv. sect. Microstegium (Nees) Roberty (1960) 388. — [ Microstegium Nees sect. Viminea Tzvelev (1961) 22, nom. inval.]. — Type: Microstegium willdenovianum Nees , nom. superfl. [= Microstegium vimineum (Trin.) A.Camus ], see note.

Pollinia Trin. (1832) 304, non Spreng. (1815). — Lectotype: Pollinia spectabilis Trin. [= Microstegium spectabile (Trin.) A.Camus ], designated by Keng (1939: 297).

[ Ephebopogon Nees & Meyen ex Steud.(1840) 556,nom.inval. — Voucher: Ephebopogon gratus Nees & Meyen ex Steud. [= Microstegium fasciculatum (L.) Henrard].

Coelarthron Hook.f. (1896a) 163. — Type: Coelarthron brandisii Hook.f. [= Microstegium brandisii (Hook.f.) Rhind ].

Ischnochloa Hook.f.(Apr. 1896a) 147; (May 1896 b) t. 2466. — Type: Ischnochloa falconeri Hook.f. [= Microstegium falconeri (Hook.f.) Clayton ].

Microstegium Nees sect. Monantha Honda (1930) 403, 409. — Type: Microstegium monanthum (Nees ex Steud.) A.Camus. [= Microstegium fasciculatum (L.) Henrard].

Pogonatherum P.Beauv. sect. Ischaemopsis Roberty (1960) 381. — Type: Pogonatherum rufispica (Steud.) Roberty [= Microstegium rufispicum (Steud.) A.Camus ].

Annuals or perennials. Ligule a glabrous to ciliate collar-shaped membrane, rarely absent. Leaf blades sometimes pseudope- tiolate. Inflorescence espatheate, composed of spicate main branches, solitary or digitate, subdigitate, or non-digitate, usually disarticulating transversally at the joints, joints slen- der, linear or not, joints and pedicels without a longitudinal, translucent furrow. Pedicel free of the rachis. Spikelets in sessile and pedicellate pairs, dorsoventrally compressed; callus short. Glumes awned or muticous, very dissimilar; lower glume rounded to sulcate on the back, 4– 6-nerved; upper glume cymbiform, 3-nerved. Sessile spikelets without a pedicel, deciduous with the adjacent joint and pedicel of the pedicelled spikelet, with incomplete florets, lower floret well-developed, bisexual, to reduced to absent, lower lemma and palea variously reduced to both absent. Upper lemma acute to deeply cleft, muticous to 1-awned from the apex or sinus, awn with or without a column, then either wavy or geniculate, glabrous. Upper palea present or not. Lodicules absent, or 2. Stamens 1–3. Styles 2, free to their bases. Caryopsis not grooved; hilum short; embryo large. x = 10.

Distribution — At least 16 species and one variety in the (sub)tropics of the Old World.

Notes — According to the Nees manuscript in E Leptatherum and L. royleanum were renamings of Pollinia Trin. and P. nuda Trin. (Dr. H.J. Noltie, in litt.).

The type of Microstegium willdenovianum has not been found in the Willdenow herbarium (B, using IDC microfiche 7440), making the correct application of the generic name somewhat uncertain. Nees’s description, however, refers clearly enough to the current concept. Steudel (1854b: 411), who saw Nees’s specimens in B, cited Arthraxon 8838 Wall. Cat. (the type of Andropogon vimineus ) Panicum – Hornem. in Herb. Willd. As the specimen was collected in Nepal, it most likely would also be a Wallich collection, many of which, if not all, Willdenow got through Hornemann. There is no Arthraxon , Leptatherum , Microstegium , or Pollinia listed in the catalogue to the IDC microfiche. The specimen was not found under Panicum (or Andropogon and some other educated guesses).