Quararibea alversonii C.D.M. Ferreira; Bovini & Baumgratz, 2022

Ferreira, Carlos D. M., Bovini, Massimo G. & Baumgratz, José Fernando A., 2022, Quararibea alversonii (Malvaceae; Malvoideae), a new species from the Brazilian Atlantic Forest, Phytotaxa 547 (2), pp. 208-214 : 209-212

Quararibea alversonii C.D.M. Ferreira; Bovini & Baumgratz , sp. nov. ( Figs. 1 & 2 )

Type:— BRAZIL: Bahia: Camacã, RPPN Serra Bonita , 15°23’30”S, 39°33’55”W, 835 m [a.s.l.], 3 March 2006, A.M. Amorim et al. 5696 (holotype: CEPEC [2 sheets]! , isotypes: RB!, SP!) .

Diagnosis:—Similar to Q. amazonica Ulbrich (1908: 91) by costate calyx, but differing by the presence of pocket-like domatia on the primary vein axils (vs. absent), longer pedicels [(0.8–)1–1.2(–1.6) cm vs. 0.4–0.5 cm], narrower petals (ca. 0.6 cm vs. ca. 1.1 cm), shorter staminal columns (1.9–2.6 cm vs. ca. 3.3 cm) with sessile anthers, grouped at the apex of staminal tube (vs. subsessile anthers, distributed up to ca. 0.7 cm below the apex), styles entire (vs. bifidus), and fruits obovoid to spheroid and 1-seeded (vs. oblong to turbinate, 2-seeded).

Tree 10–20 m tall. Young branches sparsely covered with trichomes dentate-lepidote, hyaline. Petiole 0.6–1.3 cm long, petiole and stipules densely covered with trichomes dentate-lepidote, hyaline. Leaf blades 9.7–18.4(–22.2) × 4.7–7.9(– 11.6) cm, membranaceous to chartaceous, usually symmetric, elliptic to obovate, margins entire, base rounded to obtuse, apex obtuse to acuminate; adaxial surface sparsely covered with trichomes dentate-lepidote, brownish, abaxial surface densely covered with trichomes dentate-lepidote and stellate-porrect, brownish, domatia pocket-like on the primary vein axils, with sparse trichomes simple. Flowers solitary, opposite of the leaves, erect; pedicels (0.8–)1–1.2(–1.6) cm long, densely covered with trichomes fasciculate, brownish; bracteoles 3, triangular, densely with trichomes dentatelepidote, hyaline; calyx 1.1–1.9(–2.1) × 0.9–1.2(–1.4) cm, costate, densely with trichomes fasciculate, brownish, apex 2–5 lobated, lobes triangular, apex rounded to obtuse; petals 2–2.9(–3.7) × ca. 0.6 cm, both surfaces densely covered with trichomes stellate-porrect, hyaline; staminal column 1.9–2.6 cm long, 2/3-superior densely to sparsely covered with trichomes stellate-porrect, hyaline, 1/3-inferior glabrous, apex 5-toothed, teeth 0.2–0.3 cm long, glabrate; anthers sessile, grouped at the apex of the staminal column; ovary densely with trichomes fasciculate, hyaline; style entire, densely covered with trichomes fasciculate, hyaline; stigma capitate. Fruit immature (1.7–)2.6 × (1.4–) 2.2–2.4 cm, obovoid to spheroid, 1-seeded; seed 1.1–1.7 × 1 cm, biconvex, obovoid, base acute or slightly rounded, apex rounded, sometimes apiculate.

Common names:— virote, virote-bandeira (Portuguese).

Phenology:—This species flowers from February to October and produces fruit from May to August.

Etymology:—The epithet alversonii is given in honor of Dr. William Surprison Alverson, University of Wisconsin, Madison, for his valuable contributions to the study of Malvaceae , especially the Matisieae tribe. His extensive work in Mexico and Central America ( Alverson, 1986) helped botanists understand the circumscription of Quararibea , a genus that many authors before him treated as synonymous with Matisia Humboldt & Bonpland (1808: 9) , but which he later showed to be distinct genera ( Alverson 1989).

Distribution and habitat:— Quararibea alversonii is restricted to the State of Bahia ( Figure 3 ), occurring in humid forests, with some populations at elevations from 800 to 1,000 m a.s.l., such as the populations of Camacã and Arataca. These higher elevation populations contrast to other species of Quararibea from the Atlantic Forest, which typically do not occur above 700 m a.s.l. Quararibea alversonii is also found in anthropic areas, often in cocoa plantations, such as the populations in Ilhéus, Itabuna, Una, and Uruçuca.

Conservation status:—The species is endemic to southern Bahia State with EOO less than 10,000 km ² and AOO less than 40 km ². Of the 12 existing records for the taxon, only four are protected by conservation units, such as Parque Nacional e Histórico do Monte Pascoal, RPPN Serra Bonita and RPPN Caminho das Pedras. Some localities for the species have already been directly threatened by degradation, through such activities as agricultural and pastoral expansion. Moreover, this species has not been collected from the wild for about 15 years, with the last known record from 2006, suggesting the rarity of the species and progressive decline of unprotected populations. Therefore, Q. alversonii is herein considered EN [B1 B2 b (i, ii, iii)].

Discussion:— Quararibea alversonii is mainly recognized by its costate calyx. The only other species occurring in Brazil with a costate calyx is Q. amazonica , endemic to Amazon State and morphologically distinct from Q. alversonii by leaf, flower and fruit characteristics ( Table 1 ). Regarding vegetative characteristics, the pocket-like domatia of Q. alversonii resemble to those of Q. bragae C.D.M. Ferreira & Bovini (2020: 225) , Q. penduliflora (A. St.-Hil. 1825: 269) K. Schumann (1886: 241), and Q. turbinata (Sw. 1788: 102) Poiret (1816: 636) . Quararibea bragae is easily differentiated from Q. alversonii by the location of its domatia, which occur on the axils of primary, secondary and tertiary veins (vs. only in the axils of the primary vein in Q. alversonii ). Reproductive structures distinguish Q. penduliflora and Q. turbinata from Q. alversonii , as follows: a staminal column with an undulate apex (vs. column 5-toothed in Q. alversonii ), the indumentum of the staminal column composed of stellate-porrect trichomes (vs. fasciculate in Q. alversonii ), the transversely ellipsoid fruits (vs. obovoid to spheroid in Q. alversonii ), and with 2–3 seeds per fruit (vs. 1-seeded in Q. alversonii ).

Additional specimens examined:— BRAZIL. Bahia: Arataca, Serra do Peito-de-Moça , RPPN Caminho das Pedras , 15°10’25”S, 39°20’30”W, 1000 m a.s.l., 13 Apr. 2006, fl., A.M. Amorim et al. 5745 ( CEPEC 111639 ) ; ibid., 5 Aug. 2006, fr., M.M.M. Lopes et al. 990 ( CEPEC 112692 ) ; ibid., 15°10’27”S, 39°20’22”W, 450–800 m a.s.l., 22 July 2005, fr., J.G. Jardim et al. 4732 ( CEPEC 114061 ) ; Ilhéus, Faz. Pirataquissé , 24 July 1944, fl., H.P. Vellozo 893 ( R 41345 ) ; ibid., CEPEC , 11 Mar. 1969, fl., J.A. Jesus 391 ( CEPEC 5101 , R 135406 ) ; ibid., 19 Apr. 1983, fl., T.S. Santos 3860 ( CEPEC 31230 ) ; Itabuna - Uruçuca, 6 July 1965, fl., R.P. Belém 1312 ( CEPEC 1094 ) ; Itamaraju, Monte Pascoal [ Parque Nacional e Histórico do Monte Pascoal ], 3 Oct. 1966, fl., R.P. Belém & R.S. Pinheiro 2706 ( CEPEC 2483 ) ; Una, Faz. S. Rafael , 16 Feb. 1966, fl., R. Pinheiro 58 ( CEPEC 1919 ) ; Uruçuca, Água Preta , 10 May 1936, fl., J. Aragão 5080 ( SP 37137 ) ; Wenceslau Guimarães, May 1996, fr., A.E. Brina & L.V. Costa s.n. ( BHCB 36321 ) .

Figures

FIGURE 1. Quararibea alversonii. a. floriferous branch; b. leaf (abaxial surface); c. detail of pocket-like domatia; d. polar view of the bud, evidencing the costate calyx; e. flower; f. pedicel and calyx; g. staminal column; h. detail of the staminal column apex and anthers; i. immature fruit.Photos: C.D.M. Ferreira, based on A.M.Amorim 5696 (a, d), A.M. Amorim 5745 (b, c), R.P. Belém 1312 (e–h), and M.M.M. Lopes et al. 990 (i).

FIGURE 2. Detail of the floriferous branch of Quararibea alversonii. Photo: A.M. Amorim.

FIGURE 3. Geographical distribution of Quararibea alversonii (circle).