Calyptranthes irregularis Sobral, M.A.D.Souza & B.Luize, 2015

1. Calyptranthes irregularis Sobral, M.A.D.Souza & B.Luize View in CoL , nov. sp.

Type:— BRAZIL. Amazonas: mun. Codajás, paisagem lago Badajós, margem esquerda (norte) Solimões , 03°33’75” S, 62°44’15” W, 23 July 2011, B.G. Luize 411 (holotype INPA! , isotype RB! ). Figure 1 View FIGURE 1 .

This species is related to Calyptranthes cuspidata , from which it is distinguished by the blades with adaxially impressed midveins (vs. plane or raised in C. cuspidata ), strictly terminal inflorescences (vs. terminal and axillary), larger flowers buds (to 8 mm vs. up to 5 mm) with white or grey trichomes (vs. brown trichomes) tearing irregularly at anthesis, either forming a calyptra or not (vs. always forming a calyptra).

Tree to 10 m. Cortex grey or red, striate, with vertically elliptic lenticels. Twigs terete or subquadrate, the younger ones with simple gray or yellowish simple ascending trichomes 0.2–0.3 mm, these falling with age; internodes 40–75 × 2–3 mm. Petioles 4–8 × 0.8–2 mm, glabrous or with trichomes as the twigs, markedly sulcate adaxially when dry; blades elliptic to narrowly elliptic, 87–165 × 30–69 mm, 2.2–3.2 times longer than wide, markedly discolorous, lighter abaxially, the adaxial side mostly glabrous, sometimes with scattered whitish dibrachiate trichomes to 0.5 mm, the abaxial side densely covered by simple grey ascending trichomes 0.1–0.2 mm, some longer trichomes to 1 mm scattered along the midvein; glandular dots 6 to 10/mm², 0.05 mm in diameter or smaller, visible adaxially or when against light; apex acuminate to 5–15 mm; base cuneate; midvein impressed and sometimes lighter than the adaxial surface and abaxially prominent; lateral veins 16 to 20 at each side, leaving the midvein at 70–80°, adaxially moderately raised and sometimes lighter than the surface, abaxially markedly raised; secondary lateral veins and higher level venation usually visible and sometimes slightly raised on both sides; marginal vein 1–2.1 mm from the plane or undulate margin. Inflorescences terminal, never inserted in the axils of the distal leaves in examined material, but emerging opposite to them, with 5 to 30 flowers, with trichomes as the twigs, 30–90 × 2–2.5 mm, spiciform to paniculiform, in this case with all branches strictly opposite to each other and the main axis aborted after the first or second pair of secondary branches, these with up to 45 mm; bracts triangular, slightly concave, to 4 × 2–3 mm, with trichomes to 0.3 mm abaxially; bracteoles oblong, slightly concave or plane, to 3 × 1 mm, apiculate, with trichomes to 0.5 mm abaxially; flower buds obovate, 7.5–8 × 5–5.5 mm, densely and more or less uniformly covered with simple grey trichomes to 1 mm, these sometimes denser at the basal portion; calyx lobes completely fused, forming an apiculum 1.6–2 mm, tearing at anthesis more or less irregularly in four to five lobes, 1.5–3.5 × 2–3 mm, the apiculum either remaining intact in one large lobe and resembling a calyptra, or tearing in two parts, forming two distinct calyx lobes; petals obovate or spathulate, 3–4 × 2–2.5 mm, glabrous adaxially and densely covered abaxially with white simple trichomes to 0.5 mm; staminal ring to 3 mm in diameter; stamens more than 200, glabrous, to 6 mm, the anthers globose, 0.2–0.3 mm in diameter, eglandular or with a small central gland; calyx tube 2–3 mm deep, with trichomes to 0.5 mm; style to 10 mm, glabrous, the stigma punctiform and minutely papillose; ovary with two locules and two ovules per locule. Fruits globose, immature in the specimens examined, 8–10 mm in diameter, with simple ascending grey trichomes to 0.2 mm; seeds very young, not examined.

Distribution, habitat, phenology:—This species is presently known from the municipalities of Anori and Codajás, in the central portion of the northern Brazilian state of Amazonas, where it grows in floodable forests (“várzea”); flowers were collected in July and August and fruits in August, along periods where the forest was flooded and only canopies of trees were above water level.

Affinities:—The flowers of Calyptranthes irregularis either open through a well-defined calyptra or an irregular splitting of the lobes, a morphology intermediate between the genera Calyptranthes Swartz (1788: 79) , defined by the anthesis through one circular piece, and Marlierea Cambessèdes (1832 –1833: 373), characterized by a calyx that tears in irregular lobes. These two genera are recognized as closely related and were merged by Lucas et al. (2011), together with Gomidesia O. Berg (1855 –1856: 27) and Myrcia De Candolle (1827: 406) in the assemblage dubbed the “ Myrcia group”. Lucas et al. (2011) note that recognizing only one generic name for this clade would be phylogenetically more sound; nevertheless, Calyptranthes is the older name and until Myrcia might be conserved against it (for details of proposal to conserve, see Lucas & Sobral 2011), the name to be taken for this group is still debatable. Since this proposal must wait for a future official decision of the International Association for Plant Taxonomy, both names are still currently used and we then assign this species to Calyptranthes . Calyptranthes irregularis is apparently related to the Amazonian Calyptranthes cuspidata Martius ex De Candolle (1828: 258 ; see also Berg 1857 –1859: 39; image: K barcode 000331104!), from which it is distinguished by the characters given in the diagnosis.

Conservation:—This species was collected in two contiguous scarcely surveyed municipalities of the state of Amazonas, Anori and Codajás, with respectively 5,700 km ² and 18,700 km ² ( IBGE 2015b) and 360 and 282 collections ( CRIA 2015). Since the collections of this species bear geographical coordinates, it was possible to estimate its extent of occurrence via Geocat ( Bachman et al. 2011), which is of 800 km ², an area smaller than 20,000 km ² (criterion B1 for Vulnerable, see IUCN 2001); considering that the species is known from three locations, it fulfills criterion B2a for Vulnerable; although a thorough evaluation would need information about the quality of environment, we do not have these data (see criteria B2b in IUCN 2001). So, even with an incomplete set of data, we suggest this species to be scored as Vulnerable (VU) according to IUCN criteria.

Etymology:—The epithet is allusive to the irregular opening of the flowers of this species.

Vernacular names:—Araçá-folhão (Luize 321) or araçá-roxo (Luize 123).

Paratypes:— BRAZIL. Amazonas: mun. Anori, divisa de município Beruri, RDS [Reserva de Desenvolvimento Sustentável] Piagaçu-Purus, setor Itapuru, baixo rio Purus , 04°24’22” S, 62°03’57” W, 06 August 2009, B.G. Luize 123 ( INPA!) GoogleMaps . Codajás, paisagem lago Badajós, margem esquerda (norte) Solimões , 03°31’21” S, 62°37’06” W, 17 July 2011, B.G. Luize 321 ( HUFSJ!, INPA!, MG!, RB!) GoogleMaps .