Murdannia burchellii (C.B.Clarke) M.Pell., 2016

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 : 41-43

1. Murdannia burchellii (C.B.Clarke) M.Pell. comb. et stat. nov. Figs 1 , 10

Aneilema gardneri var. burchellii C.B.Clarke, Monogr. Phan. 3: 217. 1881. Lectotype (designated here): BRAZIL. s.loc., fl., fr., s.dat., W.J. Burchell 8165 (K barcode K000363240!; isolectotypes: GH barcode GH00415446!, P barcode P02088020!).

Aneilema gardneri var. glabrior C.B.Clarke, Monogr. Phan. 3: 217. 1881. Lectotype (designated here): BRAZIL. Goyaz, fl., fr., 1841, G. Gardner 4020 (P barcode P02088023!; isolectotypes: BM not found, G barcode G00098263!, NY barcode NY00247402!). Syn. nov.

Description.

Herbs ca. 14.0-55.0 cm tall., perennial, rhizomatous with a definite base, terrestrial to paludal to rooted emergent in flooded fields. Roots thin, fibrous, brown to dark-brown, densely to sparsely pilose with medium to dark brown hairs, emerging from the rhizome and from the basal most nodes. Rhizomes short, light to medium brown, buried in the sand or ground. Stems trailing with ascending apex, thin, densely branched or branched only at the base; internodes 1.8-8.4 cm long, green to vinaceous to reddish brown, sparsely pilose to hispid with hyaline hairs, becoming glabrous with age, with a line of eglandular hyaline hairs opposite the leaf above. Leaves spirally-alternate, evenly distributed along the stems, the distal ones gradually smaller than the proximal ones; sheaths 0.3-1.3 cm long, vinaceous to reddish brown, sparsely pilose to hispid with hyaline hairs, becoming glabrous with age, hairs hyaline, margins setose, with a line of eglandular hairs opposite to the leaf above; lamina 2.7-13 × 0.3-0.6 cm, linear to linear oblong, membranous, conduplicate, slightly falcate, light green to greyish green on both sides, drying light brown to olive-green on both sides, sparsely pilose to hispid, becoming glabrous with age, rarely glabrous, base truncate, margins green, ciliate to setose throughout or only at base, apex acuminate to mucronate; midvein conspicuous, impressed adaxially, prominently acute abaxially, secondary veins 2-(3) pairs, adaxially inconspicuous to slightly conspicuous, dark green, abaxially somewhat conspicuous, dark green. Inflorescences 1-2-(4) thyrsi, terminal or axillary in the uppermost nodes, thyrse with (1-)2-16, alternate to subopposite cincinni; peduncles 2.3-7.6 cm, with a sparse mixture of eglandular (scabrid) and glandular, hyaline hairs; basal bract reduced or leaf-like, 1.4-5.1 × 0.1-0.3 cm, lanceolate to linear, sparsely pilose to hispid, rarely glabrous, base truncate, margins ciliate to setose, apex acuminate, veins inconspicuous, concolorous or green; cincinni bracts ca. 0.2-1.1 × 0.1-0.4 cm, triangular to broadly triangular, cup-shaped, light green to lilac, glabrous to pilose at base, base amplexicaul, non-perfoliate, margins glabrous to sparsely ciliate, apex caudate; cincinni 2-9-flowered, erect, sinuate, cincinnus peduncle 0.4-2.2 cm, green to vinaceous to purple, with a mixture of sparse eglandular (scabrid) and sparse or more numerous glandular, hyaline hairs, cincinnus internodes 0.2-1.1 cm long, green to vinaceous to purple, with a mixture of sparse eglandular (scabrid) and sparse or more numerous glandular, hyaline hairs; bracteoles ca. 1.8-3.7 × 0.9-1 mm, persistent, triangular to broadly triangular, cup-shaped, light green to lilac, glabrous to sparsely pilose, base amplexicaul, non-perfoliate, margins glabrous or rarely sparsely ciliate, apex acuminate. Flowers bisexual or male, enantiostylous, ca. 0.5-1.2 cm diameter; floral buds narrowly ovoid to ovoid, 2.1-4 × 1-2 mm, green to lilac; pedicels 0.3-1 cm long, green to vinaceous to purple, with a mixture of sparse eglandular (scabrid) and sparse or more numerous glandular, hyaline hairs, erect and elongate in fruit; sepals 3.2-5 × 1.5-2 mm, triangular to ovate-triangular, cucullate, green, glandular to densely glandular, hyaline hairs, apex acuminate, margins hyaline light green to hyaline lilac; petals equal, 4-6.3 × 3-4.2 mm, obovate to narrowly obovate, slightly cucullate, pale lilac to lilac to pink, rarely white, glabrous, base cuneate, margins entire, apex obtuse to rounded; stamens 3, equal, filaments glabrous, gently curved at the apex, 3.8-5.2 mm long, pale lilac to lilac or white, anthers narrowly elliptic to narrowly oblong, 0.8-1.0 × 0.3-0.7 mm, connective lilac, anthers sacs white, pollen white; staminodes 3, equal, filaments glabrous, straight, 1.6-2.1 mm long, pale lilac to white, antherodes sagittate, 0.8-0.9 × 0.9-1.0 mm, connective golden yellow, lobes conspicuous, cream-colored to pale yellow; ovary ellipsoid to oblongoid, 0.9-1.8 × 0.6-0.8 mm, 3-locular, white to light green, smooth, glabrous, style gently curved at the apex, ca. 1.8-3.6 mm, pale lilac to lilac or white, stigma truncate, white to lilac. Capsules 2.8-4.4 × 3-4.8 mm, subglobose to globose, apiculate due to persistent style, 3-locular, 3-valved, light brown when mature, glabrous, smooth. Seeds 1 per locule, 1.9-2.8 × 1.3-2.1 mm, reniform to broadly ellipsoid, cleft towards the embryotega, ventrally flattened, testa dark brown to greyish brown, densely farinose, costate to slightly rugose, with ridges radiating from the embryotega, with a tan appendage that extends ventri-laterally to the embryotega and basally into the hilum; embryotega semilateral, relatively inconspicuous, generally covered by a cream farina, without a prominent apicule; hilum linear, approximately the same length as the seed, in a deep depression.

Specimens seen.

BOLIVIA. Santa Cruz: San Ignacio de Velasco, 30 km acia S, 12 Apr 1988, B. Bruderreck 310 (LPB, US). BRAZIL. Goiás: Provincia Goyaz, Salinas, May-Jul 1844, M.A. Weddell 2103 (P); loc. cit., May-Jul 1844, M.A. Weddell 2106 (P); s.loc., 1841, G. Gardner 3481 (K); Colinas do Sul, Vila Borba, 15 Jun 1993, G. Hatschbach et al. 59587 (MBM, MO, USU); Formoso, arredores de Formoso, 3 May 2012, R.J.V. Alves 8898 (R); Paraíso, ca. 27 km sul de Paraíso, 23 Mar 1968, H.S. Irwin et al. 21659 (K, NY, UB); loc. cit., 23 Mar 1968, H.S. Irwin et al. 21717 (NY, UB); Maranhão: Carolina, 1 Jun 1950, J.M. Pires & G.A. Black 2564 (UFMA, US); Pará: Ilha do Marajó, 15 Aug 1901, fl, fr., M. Guedes 2314 (BM); Serra do Cachimbo, Jun 1955, M. Alvarenga s.n. (RB 90541); loc. cit., 12 Dec 1956, J.M. Pires et al. 6104 (NY, UFMA); Itaituba, arredores da base aérea do Cachimbo, 25 Apr 1983, M.N. Silva et al. 90 (INPA, K, MG, NY, US); loc. cit., 26 Apr 1983, M.N. Silva et al. 118 (INPA, MG, NY, US); Piauí: Piauhy, Parnaguá, marshy places, Aug-Sep 1839, fl., fr., G. Gardner 2743 (BM, K); Tocantins: Araguaina, 20 km ao Sul, 26 Mar 1976, G. Hatschbach & R. Kummrow 38378 (MBM, US). VENEZUELA. Apure: Departamento Muñoz, módulos F. Corrales de la UNELLEZ, entre los caños Guaritico y Caicara, 25 Oct 1980, B. Stergios 2379 (PORT, US); loc. cit., 10 Sep 1981, fr., G. Aymard 466 (PORT); loc. cit., 13 Sep 1981, B. Stergios et al. 9568 (PORT, US); loc. cit., 9 Dec 1986, G. Aymard & R. Schargel 5017 (PORT, US); loc. cit., 12 Dec 1986, G. Aymard & R. Schargel 5071 (PORT, US); Cojedes: San Carlos, en extremo Sur del Hato "El Laurel", mas o menos km. 17 al sur de San Carlos, 21 Aug 1976, fl., fr., B. Trujillo 13843 (MY); Guárico: Calabozo, ca. 39 km SSW of Calabozo on Hato Masaguaral, 17 Sep 1983, R. Rondeau 469 (US); Portuguesa: Guanare, terrenos de la UNELLEZ, Mesa de Cavacas, 6 Sep 1986, fl., fr., B. Stergios 7151 (PORT).

Distribution and habitat.

Murdannia burchellii has a very fragmented distribution, probably due to lack of collections, being known to occur in Bolivia, Brazil (in the states of Goiás, Maranhão, Pará, Piauí and Tocantins), and Venezuela (Fig. 10 ). It grows in shady to open sandy river banks of the Amazon and Cerrado domains.

Phenology.

It was found in bloom and fruit from October to July.

Conservation status.

Murdannia burchellii possesses a wide EOO (ca. 3,513,319.273 km2), but due to the few and scattered collections known for this species, its AOO is considerably smaller (ca. 22,500.000 km2). Thus, following the IUCN recommendations ( IUCN 2001), Murdannia burchellii should be considered Least Concern. Nonetheless, it is important to highlight the small number of collections and how fragmented the distribution of Murdannia burchellii is. Also, the most recent collection was made in 1993. Which may indicate an ongoing decrease of size of the subpopulations and the loss of habitat for this species.

Nomenclatural notes.

When describing Aneilema gardneri var. burchelli, Clarke (1881) lists two collections (W.J. Burchell 8165 and M.A. Weddell 2106). Since the name of Clarke’s new variety honors W.J. Burchell, it seems logical to designate his collection as the lectotype. Aside from that, this collection is well distributed in several herbaria around the world. Furthermore, the specimen from K herbarium matches Clarke’s description and has hand annotations made personally by Clarke. Thus, we designate this specimen as the lectotype for Aneilema gardneri var. burchelli.

When describing Aneilema gardneri var. glabrior , Clarke (1881) cites three collections by G. Gardner (2743, 3481, 4020). The specimen of at K Gardner 4020 is mounted on the same sheet as Gardner 3481, and both being annotated by Clarke as Aneilema gardneri var. glabrior . Gardner 4020 is also the most well distributed of the three collections. Nonetheless, the specimen of at K represents Murdannia gardneri , so it cannot be designated as the type of Aneilema gardneri var. glabrior . Thus, the specimen at K is not considered part of the original material. One of us (RBF) examined and recorded a specimen of Gardner 4020 at BM in 1993, with the following data on the label: "Moist campos between Natividade and Conceição, Feby 1840, Herb. Gardner." While this would appear to be the most logical choice for a lectotype, the specimen was not photographed when other types were photographed at BM, and it cannot be found today. Therefore, the specimen at P is here designated as the lectotype. This specimen also bears an identification in Clarke’s handwriting.

Discussion.

Murdannia burchellii is morphologically similar to Murdannia gardneri due to the general aspect of the plants, indumentum and by the presence of a ventri-lateral appendage in the seeds. It was traditionally treated as part of Murdannia gardneri s.l. due to the number of cincinni per inflorescence, the posture of the pedicels at post-anthesis and in fruit, general floral and capsule morphology, and due to the hilum being positioned in a deep depression (Table 1 ). Nevertheless, both species can be readily differentiated by the stature and robustness of the plants, the insertion of the cincinni in the main axis of the inflorescence and testa ornamentation. Furthermore, the cincinni in Murdannia burchellii are conspicuously sinuate, while the cincinni in Murdannia gardneri are straight. After analyzing the syntypes for Aneilema gardneri var. glabrior , it became clear that they were conspecific with Murdannia burchellii . All specimens possess the characteristic alternate to subopposite cincinni, being differentiated only from Murdannia burchellii by sparser eglandular and glandular hairs in the inflorescence. All the analyzed specimens possessed some type of indumentum in the inflorescence, despite Clarke’s description ( 1881) stating they were completely glabrous.

Some young specimens of Murdannia burchellii with inflorescences reduced to a solitary cincinnus, can be confused with specimens of Murdannia engelsii . Nevertheless, these can be differentiated by their glabrous stems, leaf-blades with truncate base, sinuate cincinni, cup-shaped bracteoles, and glabrous androecium and gynoecium (vs. stems with glandular hairs, leaf-blades with an amplexicaul base, straight cincinni, flat bracteoles and minutely glandular-pubescent androecium and gynoecium in Murdannia engelsii ) (Table 1 ).

Figures

Figure 1. Murdannia burchellii (C. B. Clarke) M. Pell. Lectotype of Aneilema gardneri var. burchellii (K barcode K 000363240). Photograph courtesy of Royal Botanic Gardens, Kew, London.

Figure 10. Distribution map of Neotropical Murdannia Royle. Full circles Murdannia burchellii Full stars Murdannia engelsii Triangles Murdannia gardneri Stars Murdannia paraguayensis Full squares Murdannia schomburgkiana Squares Murdannia semifoliata.