Murdannia nudiflora (L.) Brenan, Kew Bull. 7(2): 189. 1952.

Pellegrini, Marco Octavio de Oliveira, Faden, Robert B. & Almeida, Rafael Felipe de, 2016, Taxonomic revision of Neotropical Murdannia Royle (Commelinaceae), PhytoKeys 74, pp. 35-78 : 50-53

4. Murdannia nudiflora (L.) Brenan, Kew Bull. 7(2): 189. 1952. Fig. 5

Phaeneilema nudiflorum (L.) G. Brückn., Notizbl. Bot. Gart. Berlin-Dahlem 10 (91): 56. 1927.

Ditelesia nudiflora (L.) Raf., Fl. Tellur. 3: 69. 1837.

Aneilema nudiflorum (L.) R.Br., Prodromus Florae Novae Hollandiae: 271. 1810.

Commelina nudiflora L., Sp. Pl. 1: 41. 1753. Lectotype (designated by Merrill 1937): INDIA. s.loc., fl., fr., s.dat., P. Osbeck s.n. (LINN barcode LINN-HL65-12!).

Diagnosis.

Herbs annual, with a definite base, terrestrial to paludal to rooted emergent in flooded fields. Roots thin, fibrous, brown, densely to sparsely pilose, emerging from the basal most nodes. Rhizomes absent. Stems prostrate, erect to ascending apex, unbranched or branched at the base, glabrous. Leaves distichously-alternate, distributed along the stems, rarely 1-2 congested at base, the distal ones gradually smaller than the basal ones; lamina membranous, conduplicate, linear to linear-lanceolate or lanceolate-oblong, glabrous or with eglandular hairs. Inflorescences 1-(2), terminal or axillary from the uppermost node, long-pedunculate, exerted from the leaf-sheaths, consisting of a solitary cincinnus; basal bract inconspicuous; cincinni bracts cup-shaped; cincinni 2-12-flowered, pendent, bracteoles cup-shaped, caducous. Flowers bisexual or male, zygomorphic due to the position of the lateral petals; pedicels erect and elongate in fruit; sepals ovate-elliptic to ovate-triangular, cucullate, glabrous; petals subequal, obovate to spatulate to obtrullate, slightly cucullate, pale lilac to purple or mauve, glabrous; stamens 2 (opposite to the lower petals), equal, filaments gently sigmoid, closely parallel to each other, white at the base, lilac at the middle, purple at the apex, densely bearded with moniliform, purple hairs, anthers elliptic to oblong, connective bluish lilac to white, anthers sacs purple to dark purple, pollen white; staminodes 4, 1 staminode antesepalous, opposite to the lower sepal, filament white to lilac, medially bearded with moniliform, purple hairs, antherode small, white, sometimes lacking, 3 antepetalous, filaments straight, pale lilac to white, glabrous or sparsely medially bearded with moniliform, purple hairs, antherodes hastate, white to cream; ovary ellipsoid to oblongoid, 3-locular, light green smooth, glabrous, style strongly curved at the apex, white to pale lilac, glabrous, stigma capitate, lilac. Capsules 3-locular, 3-valved, ovoid to subglobose, apiculate due to persistent style, light brown when mature, smooth, glabrous. Seeds 2 per locule, broadly ellipsoid to oblongoid, not cleft towards the embryotega, ventrally ridged, testa yellowish brown to brown, foveolate-reticulate, with pale warts around depressions, farinose, appendage absent; embryotega semilateral, relatively inconspicuous, without a prominent apicule; hilum elliptic, approximately ½ the length of the seed, on a weak ridge.

Distribution and habitat.

Native to Tropical Asia to Malaysia and naturalized in West Africa, North America, Central America, the West Indies and South America; in the New World ranging from the southeastern United States to Argentina. In Brazil it is known to occur in the states of Acre, Alagoas, Amazonas, Bahia, Ceará, Goiás, Maranhão, Mato Grosso, Mato Grosso do Sul, Minas Gerais, Pará, Paraíba, Paraná, Rio Grande do Sul, Santa Catarina, São Paulo and Tocantins, in disturbed vegetation, roadsides and near rice crops.

Phenology.

It was found in bloom and fruit throughout the year.

Discussion.

Murdannia nudiflora can be easily recognized by its caduceus bracteoles, single terminal cincinni, two fertile stamens and four staminodes, and capsules with 2-seeded locules (Table 1 ).

Figures

Figure 5. Murdannia nudiflora (L.) Brenan. A Habit B detail of a stem, showing the apical and long-pedunculate inflorescence C front view of a bisexual flower. Photograph A, C by W. Vargas and B by M. E. Engels.