Material and methods
Malvastrum A. Gray, Mem. Amer. Acad. Arts, Series 2, 4(1): 21. 1849, nom. cons.
Type: Malvastrum wrightii A. Gray [= M. aurantiacum (Scheele) Walpers].
Sidopsis Rydberg, Fl. Prairie Plains Centr. N. Amer. 541. 1932.
Distribution: Central United States south through Central America and the Caribbean to San Juan, Cordoba, and Buenos Aires, Argentina. Widely introduced and naturalized in the Old World Tropics, especially common in India and Australia.
Malvastrum coromandelianum (L.) Garcke, Bonplandia 5: 295. 1857.
Malva coromandeliana: L., Sp. Pl. ed.1, 2: 687. 1753.
Type: Hortus Upsaliensis, Linnaeus (Lectotype: LINN 870.3).
Detailed examination of the recently collected specimens of Malvastrum resulted in their identity as Malvastrum coromandelianum subsp. capitato-spicatum (O. Kuntze) S.R. Hill. A key to the hdac inhibitor of Malvastrum coromandelianum is provided below to distinguish the taxon from the related subspecies and facilitate identification.
(O. Kuntze) S.R. Hill, Brittonia 32(4): 476. 1980. Malveopsis coromandeliana (L.) Morong var. capitato-spicatum O.Kuntze, Rev. Gen. 3(2): 21. 1898. Malvastrum coromandelianum (L.) Garcke var. congestum R.F. Fries, Ark. Bot. 6(2): 6. 1906. Malvastrum tricuspidatum (R. Brown in Aiton f.) A. Gray var. β capito-spicatum (O. Kuntze) Stuckert, Anales Soc. Ci. Argent. 114: 28. 1932. Malvastrum tricuspidatum (R. Brown in Aiton f.) A. Gray var. congestum (R.E. Fries) Stuckert, Anales Soc. Ci. Argent. 114: 28. 1932 (Figs. 1 and 2).
Erect perennial or annual herb up to 1.5m tall; stem vesture of longitudinally scattered narrowly bilateral closely appressed short-tuberculate 4-rayed stellate hairs rarely mixed with simple hairs; stipule 4–10mm long, subfalcate, lanceolate, acuminate; petioles 3.0–4.0cm long; blades 2.5–9.0×1.5–6.0cm, wide-ovate to ovate-lanceolate, unlobed or not infrequently shallowly 3-lobed, apex acute to acuminate, margin dentate to nearly serrate, vesture of adaxial surface of bilateral 4-rayed appressed stellate hairs; flowers at first solitary in leaf axils but later produced in congested axillary and terminal few to many-flowered glomerate or short-spicate racemes throughout the upper half of the plant and branches with short internodes; bifid floral bracts lacking, flowers subtended by reduced leaves with stipules or by stipules alone; pedicels 2–3mm long; involucel of 3 lanceolate to narrowly lanceolate slightly falcate acuminate bracteoles; calyx basally united, 5–8mm long in fruit, broadly campanulate, lobes slightly spreading in flower and erect or incurved in fruit, deltate-cuspidate, abaxial surface moderately to sparsely pubescent with primarily 4-rayed stellate hairs on veins and a ciliate margin of simple hairs, adaxial surface puberulent with minute arachnoid simple or obscurely stellate hairs on the apical portion and marginally to the sinus; corolla yellow to pale golden-yellow, 1.5–1.7cm in diam when spread, wide-campanulate or nearly rotate, the petals asymmetrically bilobed, 7–9×5–6mm; androecium with 16–26 stamens, filaments c. 0.9mm long; gynoecium with 11–13 carpels, style branched 2.0–2.5mm above the columella, each stigma conspicuously expanded and hemispherical to subglobose and subequal to slightly recurved below the anther cluster; schizocarps 5.5–6.5mm diam; mericarps 11–13, 3.0–4.5mm high, 3.0–4.0mm long, 1.3–1.5mm wide, with a single median apical cusp of 1.0–2.0mm long, and two distal cusps of 0.4–1.0mm long conspicuously divergent from one another, lateral faces conspicuously ribbed especially on the margins, vesture of the apical surface and cusps of rigid simple hairs, lateral faces glabrous or a few minute hairs near apex, distal surface minutely pubescent with medial and marginal simple or stellate hairs, mericarp indehiscent, shed from the receptacle and calyx at maturity.
Material and methods