M. tenuifolia Moq. in DC., Prodr. 13(2): 18 (1849).

Sukhorukov, Alexander P., Sennikov, Alexander N., Nilova, Maya V., Mazei, Yuri, Kushunina, Maria, Marchioretto, Maria Salete & Hanacek, Pavel, 2019, Evolutionary relationships and taxonomy of Microtea (Microteaceae), a basal lineage in the core Caryophyllales, PhytoKeys 115, pp. 1-50 : 35-36

10. M. tenuifolia Moq. in DC., Prodr. 13(2): 18 (1849).

M. maypurensis var. angustifolia Moq. in DC., Prodr. 13(2): 18 (1849). Lectotype (Sennikov & Sukhorukov, designated here): BRAZIL. Jacobina Mountains in Bahia, 1836, Blanchet 2588 (P00798998!).

Lectotype.

(designated by Nowicke 1968: 352): BRAZIL. Espírito Santo State, Pico d’Habira [Pico do Itabira], 1843, Claussen 392 (P00743993!).

Description.

Annual or short-lived perennial herb with several or numerous stems 10-40 cm high; leaves sessile (sometimes rosulate leaves shortly pedunculate), cuneate, 10-30 mm long and 0.3-3.0(5.0) mm wide; inflorescence a spike; pedicels 1.35-1.7(2.5) mm; flowers with a bract and two bracteoles, perianth segments 5, white, oblong; stamens 6-8, stigmas 3-5, thin; fruit 0.9-1.1 × 1.0-1.1 mm (Fig. 8E ), equal to perianth or slightly protruding; pericarp smooth or with small and scattered tubercles (Fig. 8F ), more or less reticulate, readily scraped off the seed; seed 0.9-1.1 mm, with rough surface (Fig. 8H ).

We report for the first time that the perianth/fruit ratio is a useful distinguishing character for this species. Also, the number of stigmas can be useful in delimiting M. tenuifolia and similar forms of M. celosioides with narrower leaves. The character set of M. tenuifolia supports its close relationship to M. maypurensis , especially the forms with reduced pericarp outgrowths. Remarkably, Moquin-Tandon (1849) described a new variety of M. maypurensis (var. angustifolia Moq.) represented by two specimens of M. tenuifolia (P00743955! and P00798998!) and one specimen containing two individuals, M. tenuifolia and a narrow-leaved M. maypurensis (leg. Blanchet 2588, P00743954!). The figure of M. tenuifolia in Calió and Pirani (2006) showing the tuberculate perianth is rather an exception, and the individuals with pericarp lacking the outgrowths have so far been collected more frequently.

Habitat.

Forest margins, rocky places; 0-1000 m.

Distribution.

Endemic to Eastern Brazil, found only in Bahia, Espírito Santo, Minas Gerais and Rio de Janeiro States (Fig. 25 ).

Specimens examined.

BRAZIL: Bahia: 4 km SW of Belmonte, 23 Mar 1974, R.M. Harley 17305 (K, P04598081, U17305, U1473428); see lectotype of M. maypurensis var. angustifolia ; Jacobina, [without date], Blanchet 153 (BM000019209); Morro do Chapeu, 1000 m, 1 Jun 1980, R.M. Harley 22924 (U1473452); Espírito Santo: see lectotype of M. tenuifolia ; Minas Gerais: [without exact location] Feb 1839, Riedel 48 (P007990000); [without exact location] 1841, Claussen 4 (P00743934); [without exact location] 1845, Widgren s.n. (M); Caldas, 5 May 1870, A. Glaziou 11 (P04598116); Caldas, 15 May 1870, A.T. Regnell s.n. (B); Serrra das Vertentes, Jun 1893, A. Glaziou 20437 (B, K, P04598119); Turvo, 24 Apr 1926, W. Hohne & A. Gehrt s.n. (PACA 76840); Buenópolis Mun., Curimatai, [without date] A. Glaziou 13127 (P04598093); Buenópolis Mun., Curimatai, [without date] A. Glaziou 19399 (P04598074); Serra do Espinhaco, 15 Feb 1969, H.S. Irwin et al. 23315 (G); Bacia do Córrego Escurona, Grão Mogol, 2 Nov 1987, M.C. Assis & al. s.n. (PACA 76297); Vale do Rio Itacambiruçu, Grão Mogol, 10 Dec 1989, A. Freire-Fierres et al. s.n. (PACA 76298); Vale do Córrgo Escurona, Grão Mogol, 13 Jun 1990, A.A. Oliveira et al. s.n. (PACA 76299); Serra dos Inconfidentes, Pico do Itabirito, Itabirito, 4 Jan 1994, W.A. Teixeira s.n. (PACA); Estação Ecológica da Mata do Cedro, Carmópolis, 13 Jul 2004, L. Echternacht & T. Dornas 573 (PACA); Estação Ecológica da Mata do Cedro, Carmópolis, 23 Jan 2005, L. Echternacht & T. Dornas 830 (PACA); Grão Mogol Mun., Parque Estadual de Grão Mogol, 13 Apr 2006, C.V. Vidal 177 (PACA); Santana do Riacho Mun., Entre a Rodovia BR 251 e Grão Mogol, Cachoeira Véu de Noiva, 15 Mar 2007, M.S. Marchioretto 352 & 355 (PACA); Rio de Janeiro: nr Rio de Janeiro, Feb 1882, A. Glaziou 13127 (G, K); Rio de Janeiro, 1887, A. Glaziou 17748 (LE).

Figures

Figure 8. Fruits and seeds of Microtea maypurensis and M. tenuifolia: A, B fruit of M. maypurensis, enclosed in the perianth (Bolivia, La Paz Dept., Beni river, Jul 1886, H. H. Rusby 1379, LE) C, D seed of M. maypurensis (Bolivia, La Paz Dept., Beni river, Jul 1886, H. H. Rusby 1379, LE) E, F fruit of M. tenuifolia enclosed in the perianth (Brazil, Minas Gerais, Serrra das Vertentes, Jun 1893, A. Glaziou 20437, B) G, H seed of M. tenuifolia (Brazil, Jacobina Mountains in Bahia, 1836, Blanchet 2588, P 00798998). Magnification: A, E - 30 x, B, F - 100 x, C, G - 50 x, D, H - 300 x.

Figure 25. Distribution map of Microtea tenuifolia.