Murdannia schomburgkiana (Kunth) G. Brueckn ., Nat. Pflanzenfam. (ed. 2)15a: 173. 1930.

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 : 56-59

6. Murdannia schomburgkiana (Kunth) G. Brueckn., Nat. Pflanzenfam. (ed. 2)15a: 173. 1930. Figs 7 , 10

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

Aneilema schomburgkianum Kunth, Enum. Pl. 4: 661. 1843. Lectotype (designated here): GUYANA. s.loc., fl., fr., Oct 1841, R.H. Schomburgk 842 (B barcode B100367820!; isolectotypes: 2 ex BM not found, G barcodes G00176335!, G00176336!, G00176337!, P barcodes P02088026!, P02088027!, TCD barcode TCD0008088!).

Description.

Herbs ca. 30.0-65.0 cm tall, perennial, rhizomatous with a definite base, terrestrial to paludal to rooted emergent in open flooded savannas. Roots tuberous, thick and fusiform, medium to dark brown, densely to sparsely pilose with medium to dark brown hairs, emerging from the short rhizome and from the basal nodes. Rhizomes short, brown, buried in the sand or soil. Stems erect, succulent, unbranched; internodes 1.0-11.5 cm long, green to vinaceous, glabrous, sometimes with a line of hyaline eglandular hairs opposite the leaf above. Leaves spirally-alternate, evenly distributed along the stems, sessile, the distal ones gradually smaller than the basal ones; sheaths 0.8-2.2 cm long, green to vinaceous, glabrous, with a line of hyaline, eglandular hairs opposite the leaf above; lamina 2.2-14 × 0.4-1.0 cm, membranous to succulent, canaliculate, slightly falcate, green on both sides, glaucous, drying olive-green to light green on both sides, linear-elliptic to linear-lanceolate, glabrous, base truncate to rounded, margins light green, glabrous, apex acuminate; midvein slightly conspicuous to inconspicuous, slightly impressed adaxially, slightly obtuse abaxially, secondary veins 2-3-(4) pairs, adaxially inconspicuous to slightly conspicuous, light green, abaxially slightly conspicuous. Inflorescences 1-4, terminal or axillary in the uppermost nodes, fascicle-like, composed of 1-2-(3) verticillate cincinni; peduncles absent; basal bract inconspicuous; cincinni bracts 1.6-1.8 × 0.3-0.4 cm, tubular, amplexicaul; cincinni 1-flowered, erect, straight, peduncle 1.0-1.9 cm long, light green to pink or vinaceous, glabrous; bracteoles inconspicuous, generally caducous. Flowers bisexual or male, actinomorphic, ca. 1.3-2.3 cm diam.; floral buds ellipsoid, 5.0-5.8 × 1.5-1.8 mm, light green to pink; pedicels 0.6-1.1 cm long, light green to pink to vinaceous, glabrous, erect and elongate in fruit; sepals 6.5-10.0 × 3.2-4.1 mm, triangular to ovate-triangular, cucullate, pink to pinkish brown, glabrous, apex acute, margins hyaline pink to hyaline vinaceous; petals equal, 0.8-1.3 × 0.8-1.0 cm, obovate to broadly obovate, slightly cucullate, lilac to purple, medially bearded with lilac to purple, moniliform hairs on the adaxial surface, base cuneate, margins entire, apex acute to obtuse; stamens 3, equal, filaments gently curved at the apex, 4.4-5.2 mm long, lilac to purple, densely bearded with moniliform, lilac to purple hairs, hairs slightly shorter than the filaments, anthers elliptic to oblong, 1.7-2.4 × 0.6-1.0 mm, connective brown, anthers sacs brownish lilac, pollen brownish lilac; staminodes 3, equal, filaments straight, 4.1-5.0 mm long, pale lilac to lilac, densely bearded with moniliform, lilac to purple hairs, hairs slightly shorter than the filaments, antherodes hastate, 0.9-1.7 × 1.3-1.7 mm, connective golden yellow, lobes conspicuous, cream-colored to pale yellow; ovary ellipsoid to oblongoid, 1.9-3.1 × 0.7-1.3 mm, 3-locular, light green to green, smooth, glabrous, style gently curved at the apex, ca. 4.1-5.4 mm, lilac to purple, stigma capitate, lilac to purple. Capsules 5.9-8.5 × 2.8-4.6 mm, 3-locular, 3-valved, oblongoid to broadly oblongoid, apiculate due to persistent style, light brown when mature, smooth, glabrous. Seeds (immature) 6 per locule, 2.7-3.3 × 2.6-3.1 mm, cuboid to polygonal, slightly cleft towards the embryotega, testa dark brown to greyish brown, densely farinose, scrobiculate, with ridges radiating from the embryotega; embryotega semilateral, relatively inconspicuous, without a prominent apicule, generally covered by a cream farina; hilum linear, ½ the length of the seed or smaller, on a weak ridge.

Specimens seen.

BRAZIL. Amazonas: Provincia do Rio Negro, Rio Madeira, fl., s.dat., s.leg. s.n. (P barcode P03653202); s.loc., fl., Oct 1894, A.R. Ferreira 755 (K). GUYANA. Rupununi District: foot of Mount Shiriri, fl., 19 Jun 1995, M.J. Jansen-Jacobs et al. 4175 (P, U, US); loc. cit., Manari, Takatu river, fl., 5 Aug 1995, M.J. Jansen-Jacobs et al. 4764 (U, US); loc. cit., upper Rupununi river, fl., Appun 2361 (K).

Distribution and habitat.

Murdannia schomburgkiana is known from only four collections from Guyana (including the type) and perhaps only one collection from Brazil (in the state of Amazonas) (Fig. 10 ). It grows in open flooded grass fields and savannas in the Amazon domain. The distance between the Rio Madeira specimen and the other specimens collected in Guyana, make clear how poorly collected this species is. It is widely possible that field trips focusing on the group or in the white sand formations in the state of Amazonas will fill this distribution gap.

It is interesting to highlight that both specimens from Brazil might represent different sheets of the same collection. Firstly, it is known that Dr. Alexandre Ferreira collected exclusively in Brazilian territory. Thus, despite the locality not being clearly stated in the label of the specimen at Kew, this is the only possible option. Secondly, the specimen at Paris was collected in Brazil, Provincia Rio Negro, at the margins of Rio Madeira (currently state of Amazonas). This was one of the most important areas collected by Ferreira, during his philosophical travels, and probably the longest part of this fieldtrip. Also, it is widely known that many specimens collected by Friar Vellozo, Dr. Vellozo de Miranda and Dr. Alexandre Ferreira, were taken from Lisbon to Paris, during the Napoleonic Wars. Finally, the labels of both specimens possess comple mentary information, where the locality in the label of the Paris’ specimen is one of locations where Ferreira collected, and the date is congruent with this specific fieldtrip. Moreover, the specimens on both sheets are very similar in appearance.

Phenology.

It was found in bloom from June to October, and in fruit in October.

Conservation status.

Murdannia schomburgkiana is only known from five (or at most six) collections, including the type species. Furthermore, the last known collections for this species are 11 years old, and the AOO of Murdannia schomburgkiana is of only ca. 12.000 km2. Following the IUCN recommendations ( IUCN 2001), Murdannia schomburgkiana should be considered Endangered [EN, B1a+C2a(ii)+D1].

Nomenclatural notes.

When describing Aneilema schomburgkiana , Kunth (1843) mentions "Rob. Schomburgk misit sub. no. 842". According to Stafleu and Cowan (1985), Robert Schomburgk’s collections are generally housed at BM or K. Despite having found two specimens at BM, the specimen at B (B100367820) possesses the annotation "Ex. herb. Kunth misit. 1841.", made in Kunth’s handwriting and matching the protologue, and it is widely known that Kunth’s herbarium was part of B ( Stafleu and Cowan 1979). Thus, it was the obvious choice for a lectotype. The two sheets at BM were observed and described in detail by one of us (RBF) in 1993. However, they were not photographed when other types at BM were photographed, and the specimens cannot currently be located. If found they should be treated as isolectotypes.

Discussion.

Murdannia schomburgkiana can be easily confused with Murdannia semifoliata (C.B.Clarke) G. Brückn., due to their tuberous roots, reduced inflorescences enclosed by the leaf-sheaths, cincinni bracts tubular, petals medially bearded with moniliform hairs on the adaxial surface, filaments densely bearded with moniliform hairs, the number of seeds per locule of the capsule, and seed morphology. Their petals medially bearded with moniliform hairs on the adaxial surface, are quite unique within Murdannia . As aforementioned, this character is otherwise only known in Commelinaceae in Murdannia simplex (in which the hairs are tiny and only present at the petal, being fundamentally different), and in the distantly related genera Cochliostema Lem. and Geogenanthus Ule (Tribe Tradescantieae , subtribe Dichorisandrinae ; Hardy and Faden 2004; Pellegrini in press). Nevertheless, the distribution of both species does not overlap and they grow in different environments (white sand formations vs. flooded grass fields). Murdannia schomburgkiana can be differentiated by its 2.2-13.6 cm long blades of the leaves bearing inflorescences (vs. 0.2-1.8 cm long), leaf-blades margins glabrous (vs. ciliate), cincinni bracts 1.6-1.8 cm long (vs. 0.4-1.3 cm long), and brown anthers (vs. purple) (Table 1 ).

Despite the few collections known for this species, it is the authors’ opinion that the morphological, geographical and environmental factors are enough to differentiate both species. Murdannia schomburgkiana and Murdannia semifoliata are very similar to each other, and quite distinct from the remaining Neotropical species of the genus. They are morphologically similar to some Asian and African species with fascicle-like, mainly axillary inflorescences, and 1-flowered cincinni, such as Murdannia axillaris and Murdannia triquetra .

Figures

Figure 7. Murdannia schomburgkiana (Kunth) G. Brueckn. Isolectotype of Aneilema schomburgkianum (P barcode P 02088026). Photograph courtesy of the Museum National d'Histoire Naturelle, Paris.

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.