Tradescantia boliviana (Hassk.) J.R.Grant, Novon 14(3): 299. 2004.

Pellegrini, Marco O. O., Forzza, Rafaela C. & Sakuragui, Cassia M., 2017, Novelties in Brazilian Tradescantia L. (Commelinaceae), PhytoKeys 80, pp. 1-31 : 13-17

Tradescantia boliviana (Hassk.) J.R.Grant, Novon 14(3): 299. 2004. Figs 6 , 8

Skofitzia boliviana (Hassk.) Hassk. & Kanitz, Oesterr. Bot. Z. 22: 147. 1872.

Mandonia boliviana Hassk., Flora 54: 260. 1871. Lectotype (designated by Grant 2004). BOLIVIA. Larecaja: viciniis Sorata montis colles Ullontigi ad scopulorumra dicemi n regionet emperata, fl., fr., Feb-Apr 1858, G. Mandon 1239 (L barcode L0374955!; isolectotypes: F barcode F0076407F!, G barcode G00489633!, GH n.v., K n.v., P 3ex barcodes P00376711!, P00376712!, P00376713!).

Tradescantia ambigua var. pilosula Hoehne, Relat. Commiss. Linhas. Telegr. Estrateg. Matto Grosso Amazonas 5, 5: 14. 1915. Lectotype (designated here). BRAZIL. Mato Grosso do Sul: Corumbá, fl., Feb 1911, F.C. Hoehne 4499 (R barcode R000004848!). Syn. nov.

Diagnosis.

Herbs perennial, with a definite base, terrestrial to rupicolous. Roots thick, tuberous, brown to dark-brown, densely to sparsely pilose with brown to dark-brown hairs, emerging from the rhizome and from the basal most nodes. Stems erect, succulent, unbranched, rarely branched near the base; internodes green to vinaceous to reddish brown, sometimes with vinaceous striations, densely velutine, sometimes becoming glabrous at age, hairs hyaline to light brown. Leaves spirally-alternate, evenly distributed along the stems, sessile, the apical ones gradually smaller than the basal ones; sheaths green, densely velutine, hairs hyaline to light brown, margins ciliate, hairs hyaline to light brown; lamina succulent conduplicate, medium to dark green adaxially, light to medium green abaxially, narrowly lanceolate to lanceolate, rarely ovate, adaxially sparsely velutine, sometimes becoming glabrous at age, abaxially densely velutine, hairs light brown, base truncate to rounded, margins vinaceous to reddish brown, ciliate, apex acute; midvein conspicuous, impressed adaxially, prominently obtuse abaxially, secondary veins inconspicuous to slightly conspicuous on both sides. Inflorescences (main florescences) consisting of a sessile double-cincinni fused back to back, axillary in the uppermost nodes; peduncles inconspicuous; basal bract inconspicuous, tubular, hyaline, glabrous; peduncle bracts absent; supernumerary bracts sometimes present, 1-3 per inflorescence, similar in shape and size to the cincinni bracts; cincinni bracts reduced, light green, hispid, base non-saccate; cincinni (4-)8-22-flowered; bracteoles inconspicuous, imbricate, linear-triangular to triangular, hyaline. Flowers bisexual, actinomorphic, flat (not forming a floral tube); floral buds narrowly ovoid, dark pink to vinaceous; pedicels dark pink to vinaceous, densely glandular-pubescent, hairs light brown; sepals 3, equal, ovate, cucullate, dorsally not keeled, dark pink to vinaceous, rarely green, densely glandular-pubescent, hairs light brown, apex acute, margins hyaline light-green, persistent in fruit; petals 3, equal, sessile, broadly ovate, medium to dark pink to mauve, rarely white or light pink to lilac, base cuneate, margins entire, apex acute; stamens 6, equal, filaments light medium to dark pink to mauve, medially bearded with moniliform, medium to dark pink to mauve hairs, straight at anthesis, coiling at post anthesis, connective expanded, quadrangular, yellow to orange, anthers sacs curved, yellow, pollen yellow; ovary oblongoid, 3-loculate, white, smooth, velutine at apex, style straight, medium to dark pink, stigma capitulate, white to light pink, pistil longer than the stamens. Capsules broadly oblongoid, apiculate due to persistent style apex, green when immature, brown when mature, sparsely velutine at the apex, smooth, 3-valved. Seeds uniseriate, 2 per locule, ellipsoid to broadly ellipsoid, not cleft towards the embryotega, ventrally flattened, testa grey to greyish brown, farinose, scrobiculate arranged in ridges radiating from the embryotega; embryotega dorsal, conspicuous, with a prominent apicule; hilum linear, as long as the seed.

Specimens seen.

BRAZIL. Mato Grosso do Sul: Campo Grande, Empraba Gado de Corte, fl., fr., 28 Feb 2009, V.J. Pott 10452 (CGMS, HURB); Corumbá, fl., Feb 1911, F.C. Hoehne 4723 (R); loc. cit., Mineração Corumbaense Reunida SA, paredão próximo ao paiol de esplosivos, fl., fr., 23 Feb 2005, G.A. Damasceno-Junior et al. 3488 (COR, K); loc. cit., Serra Urucum, fl., fr., 24 Feb 2005, A. Pott et al. 12655 (CGMS, HMS); loc. cit, Fazenda Banda Alta, fl., 11 Jan 2007, A. Takahasi & S.M. Ribas 1175 (COR); Ladário, Fazenda São Sebastião do Carandá, fl., fr., 13 Mar 2003, G.A. Damasceno-Junior et al. 2773 (COR); Nioaque, Assentamento Andalucia, fl., 6 Dec 2008, L.C.S. Magalhães & G.A. Damasceno-Júnior 138 (CGMS, HURB); loc. cit., fl., fr., 9 Jan 2009, L.C.S. Magalhães & T.S. Amaral 194 (CGMS, HURB); loc. cit., fl., fr., 9 Jan 2009, L.C.S. Magalhães & T.S. Amaral 195 (CGMS); loc. cit., fl., fr., 8 Feb 2009, L.C.S. Magalhães & T.S. Yule 278 (CGMS).

Distribution and habitat.

Tradescantia boliviana restricted to Argentina, Bolivia, Paraguay, Peru, and Brazil (state of Mato Grosso do Sul). It commonly grows as rupicolous in rocky walls and outcrops, under full sunlight, in the Chaco and Pantanal domains (Fig. 8 ).

Phenology.

It was found in bloom and in fruit from December to June.

Conservation status.

Tradescantia boliviana possesses a wide EOO (ca. 2,249,457.700 km2), and based solely on this criterion it should be considered Least Concern (LC). Nonetheless, its AOO is considerably reduced (ca. 172.000 km2), added to that fact that most of the studied specimens are at least more than 20 years old. Thus, following the IUCN (2001) recommendations, T. boliviana should be considered Endangered [EN, A2bcd+B2ab(ii, iii, iv, v)+C1+C2a(i)].

Nomenclatural notes.

In the protologue of T. ambigua var. pilosula , Hoehne (1915) mentions two collections of his own when describing this new variety. The author makes no reference as to the herbarium in which each specimen is placed or to the existence of possible duplicates. According to Stafleu and Cowan (1979), Hoehne’s types are generally at SP with duplicates in several other herbaria. However, after two visits to the SP we were unable to locate any of the specimens (Hoehne 4499, 4723). Nonetheless, Stafleu and Cowan (1979) make an important remark that until 1917, Hoehne was living and working in Rio de Janeiro. After analyzing the collection of R, we came across both specimens placed in the general collection. Both specimens were annotated by Hoehne, but the specimen Hoehne 4499 possesses a beautiful illustration attached to it, showing the details of the plants’ floral morphology. Thus, it is designated by us as the lectotype for T. ambigua var. pilosula .

Morphological notes.

Tradescantia boliviana is a morphologically variable species across its distribution. Nonetheless, in the same way as T. ambigua , there is no obvious geographical pattern in this variation. The presence of glandular hairs in the pedicels and sepals can be observed in some of the individuals, but aside from that they don’t seem to differ in any other aspect from the other specimens. This variation is peculiar, but not unrecorded in the genus, and a similar scenario is described by Pellegrini (2015, 2016) for T. cerinthoides ( T. sect. Austrotradescantia ) and by Faden (1993) for T. crassifolia ( T. sect. Mandonia ).

After analyzing the type specimens for T. ambigua var. pilosula , we noticed that the pedicels and sepals are hispid, the connectives are quadrangular, and the ovary velutine to sparsely velutine at apex. Added to that, the distribution of the specimens collected by Hoehne is congruent with the distribution of T. boliviana , but disjunctive from T. ambigua . Thus, we consider T. ambigua var. pilosula a synonym of T. boliviana .

Figures

Figure 6. Tradescantia boliviana (Hassk.) J. R. Grant. A detail of the tuberous roots B habit C detail of fertile branch, showing the conduplicate leaf-blades, and axillary inflorescences D front view of a flower at anthesis, showing the rectangular connectives and C-shaped anther sacs E detail of an immature capsule, showing the densely glandular-pubescent pedicel and sepals, and the capsule apically velutine. Photograph A-B & D by P. Christian (RarePlants. co. uk), C & E by Instituto Darwinion.

Figure 8. Distribution map of studied Tradescantia L. in the South American domains. Full squares - T. crassula; White squares - T. chrysophylla; Triangles - T. valida; Circles - T. ambigua; Stars - T. boliviana. Light green- Amazon Forest; Orange- Cerrado; Red- Caatinga; Yellow- Chaco and Pantanal; Olive-green- Pampa; Dark green- Atlantic Forest; Purple- Andean Yungas.