Tovomita manauara A. Nobre & L. Marinho, 2022

Marinho, Alexandra Monteiro Nobre Lucas Cardoso, Cabral, Fernanda Nunes, Demarchi, Layon Oreste & Sousa, Juliana Hipólito De, 2022, Tovomita manauara (Clusiaceae): a new species revealed by fruit morphology and leaf anatomy, Phytotaxa 536 (3), pp. 270-278 : 271-276

Tovomita manauara A. Nobre & L. Marinho , sp. nov. ( Figs 1 , 2 )

Type:— BRAZIL. Amazonas: Manaus, ca. 90 km N de Manaus, Distrito Agropecuário da Suframa , rodovia BR 174, km 72, depois 6 km oeste da BR, Fazenda Dimona, mata de terra-firme sobre latosolo amarelo, árvore n°3362, 02°19’S, 60°05’W, 50–125 m. a.s.l., 16 July 1992, fr., M. Nee 42991 (holotype INPA barcode INPA0096785 !; isotypes GH!, MG!, NY barcode NY01417188 !, UEC!) .

Diagnosis: — Tovomita manauara is morphologically similar to T. caloneura , and can be differentiated by the amount of secondary veins (25–36 pairs vs. up to 26 pairs in T. caloneura ), fruit morphology (4-septate and turbinate vs. 5-septate and fusiform) and anatomical aspects—secretory canals larger (> ~40 µm vs. <~20 µm), presence of collenchyma in the petiole (vs. absent), and the absence of druses in the midvein (vs. presence).

Description: —Trees 15–18 m alt., dbh ca. 30 cm; prop roots conspicuous with 1 m in height; outer bark gray, smooth, inner bark reddish; exudate yellow; proximal internodes 2.5–8.2 cm long, distal internodes 1.2–3.4 cm long. Petioles 1–2 cm long, green, slightly canaliculate, not striated, lenticels absent. Leaf blades 4.7–14.2 × 1.9–7.1 cm, brownish-green and shiny in sicco, the adaxial surface darker than the abaxial, black dots present on both surfaces, subcoriaceous, brittle, oblong or obovate, base convex or rounded, apex acute or apiculate, margin entire and slightly revolute, exudate canals conspicuous, parallel to secondary veins, visible only abaxially in sicco as blackish lines. Venation brochidodromous, midvein immersed adaxially and prominent abaxially; secondary veins in 25–36 pairs, 1–6.2 mm apart, forming an angle ca. 70º to the midvein, immersed adaxially and slightly prominent abaxially; intersecondary veins present, one or rarely two per intercostal area, similar to the secondary veins, parallel to major secondaries and reticulating near the margin, visible only abaxially in sicco; tertiary veins percurrent sinuous to reticulate; intramarginal vein present. Capsules fleshy, 2.5–5.3 × 0.9–2.4 cm, green when immature, epicarp smooth; mesocarp purplish-red, pleasantly aromatic, 4-septate, turbinate to napiform when closed, not costate, 4-lobed; pedicel slightly dilated 1–1.5(–4.4) cm long; sepals, petals and staminodes caducous, 4–stigmas persistent 2–6 mm. Seeds 4, often one is aborted, ellipsoid, aril light orange.

Additional Specimens Examined (Paratypes): — BRAZIL. Amazonas : Manaus , estrada Manaus-Porto Velho , estrada entre o lago do Castanho e o rio Araçá, em direção ao Careiro, 12 July 1972, fr., M. F . Silva et al. 564 ( INPA barcode INPA0096784 ); Distrito Agropecuário da Suframa, rodovia BR 174 , km 64, depois 23 km leste na ZF3, Fazenda Esteio , mata de terra-firme sobre latosolo amarelo, árvore n°2803, 02°23’S, 59°51’W, 27 August 1986, fr., M. J. R . Pereira s/n ( INPA barcode INPA0096786 ); ca. 90 km N de Manaus, Distrito Agropecuário da Suframa, rodovia BR 174 , km 72, depois 6 km oeste da BR , Fazenda Dimona , mata de terra-firme sobre latosolo amarelo, árvore n°3362, 02°19’S, 60°05’W, 28 June 1989, fr., E . Palheta s/n ( INPA n° 175768, NY barcode NY01417090 ); ca. 90 km N de Manaus, Distrito Agropecuário da Suframa, rodovia BR 174 , km 64, depois 23 km leste na ZF3, Fazenda Esteio , mata de terra-firme sobre latosolo amarelo, árvore n°2803, 02°23’S, 59°51’W, 26 July 1989, fr., S. S . da Silva s/n ( INPA barcode INPA0096787 , NY barcode NY01417091 ) .

Etymology: —Manauara (Portuguese) is a person who is born in the municipality of Manaus, Amazonas state, Brazil, where all the specimens came from. Besides the species, the first author is also a manauara.

Distribution, Habitat and Conservation Status: —All the known specimens of Tovomita manauara were collected in dense ombrophilous forest situated in low altitudes (between 60 and 120 m. a.s.l.), known as terra-firme forest (see physiognomic descriptions in Ribeiro et al. 1999). The area of occurrence is located on extensive tertiary sediments within the lowland plains of the Amazon, with predominantly clayey latosols (ferralsols) that are generally poor in nutrients due to long periods of leaching ( Oliveira & Mori 1999). Tovomita manauara grows in the sub-canopy stratum (15 to 20 m tall) of forests that are in a good state of conservation and, apparently do not occur in secondary forests.

Due to the few available records, which are concentrated in only two nearby locations, T. manauara is considered as having deficient data (DD) following what was adopted by Marinho & Beech (2019). The exsiccates/specimens of T. manauara were collected in the study sites of the world’s largest and longest-running experimental study of habitat fragmentation, the Biological Dynamics of Forest Fragments Project (BDFFP). This project was created in the 70’s, after the Brazilian government announced the deforestation of a large area for agricultural development in the region. As a result, forest patches of different sizes were maintained for the study of the impacts caused by the fragmentation ( Laurance & Luizão 2007). The BDFF project, in partnership with government agencies, in order to protect its study sites, implemented a protected area of 3,288 ha (Area of Relevant Ecological Interest - Biological Dynamics of Forest Fragments Project AREI – BDFFP) in 1985, which covered the known area of occurrence of T. manauara . However, nowadays, the protected area and the entire region suffer from threats due to illegal farming, logging, and hunting ( Laurance & Luizão 2007). This situation has become further aggravated by the urban expansion of the suburbs of Manaus, and the construction of small roads or trails that facilitate the illegal occupation of public lands ( Esteves 2007).

Taxonomy notes and comments: —Almost 30 years after the collection of the type materials, specimens of Tovomita manauara with flowers have not yet been collected. Despite the BDFF project operating in the area of occurrence for more than 40 years, the absence of materials with flowers may be a reflection of the lack of scheduled collection in the area. In this sense, we recommend carrying out systematic fieldwork, followed by detailed taxonomic studies to bring this and other species not yet described to the fore ( Hopkins 2019).

Tovomita manauara can be recognized among other species of the genus by a large number of secondary veins (25–36 pairs vs. up to 26 pairs in T. caloneura , Fig. 1B ), and the presence of 4-septate fruits, which are turbinate to napiform and smooth. Tovomita manauara is sympatric and morphologically similar (leaf shape, petiole, venation type) to T. caloneura . However, it has 4-carpellate and turbinate fruit (vs. 5-carpellate and fusiform in T. caloneura ) ( Fig. 1D ), and the number of carpels is one of the most important characteristics for infrageneric delimitation ( Marinho et al. 2021). Turbinate fruits also occur in T. albiflora A.C. Smith (1940: 298) and T. turbinata Planchon & Triana (1860: 283) , though T. manauara can be easily distinguished from these species by the number of secondary veins (<15 pairs in both). Napiform to turbinate fruits ( Fig. 1C ) also appear in T. colombiana L. Marinho (2018: 406) , which is a species that is endemic to Colombia and has less than 15 pairs of secondary veins ( Marinho 2018).

Anatomy: —In addition, anatomical characters are also important for distinguishing species ( Fig. 2 ). Tovomita manauara has petiole with plane-convex contour and presents the vascular cylinder with units of vascular bundles in the medullary portion of the vascular tissue, which is a closed vascular system ( Fig. 2A ), as well as the presence of idioblasts concentrated in the cortex. The petiole has about 25/+ vascular bundles ( Fig. 2B ), the secretory canals are aligned on the periphery of the epidermis, and there is the presence of druses along the parenchyma ( Fig. 2C , 3F ). The midvein presents secretory canals in the medulla ( Fig. 4A,B ) and there is no significant increase in the number of vascular bundles when compared to the petiole. In T. caloneura the petiole has a plane-convex contour and presents the vascular cylinder with units of vascular bundles in the medullary portion of the vascular tissue, collateral bundles with a ring and an internal arch ( Fig. 2D, E ). The idioblasts and canals are present in the subepidermal region and petiole cortex ( Fig. 2F ). In the midvein ( Fig. 4C ), there is a thick cuticle in the epidermis and, in the vascular system, the vascular bundles are numerous (40/+), form collateral bundles, and are a ring with an inferior arch, a biconvex arrangement with medullary phloem ( Fig. 4C, D ). The idioblasts are arranged in the subepidermal, perivascular and medulla region of the vascular system. The mesophyll is homogeneous, the palisade parenchyma has three layers and the spongy parenchyma has six layers and canals arranged in the medulla, and both tissues are adorned with idioblasts ( Fig 4E ).

Externally, Tovomita manauara and T. caloneura share hypostomatic leaves ( Fig. 3C, E ). The abaxial surface is covered with a waxy cuticle ( Fig. 3A–E ). In some regions, the cuticle covers small papillae, similar to those seen in T. vismiifolia L. Marinho (see Fig. 1 in Marinho et al. 2016b), but is smaller and less evident ( Fig. 3B, D ). Tovomita manauara and T. caloneura also share the collateral vascular bundles and consist of one ring with one inner arch, a plane-convex cross-section on the petiole, in addition to the thick cuticle on the midvein. However, they are clearly distinct when the number of vascular bundles and the presence of druses is considered, especially in the midvein, the number of idioblasts, and the diameter of secretory canals in the petiole. This information is summarized in Table 1 .

Figures

FIGURE 1. General aspect of Tovomita manauara in sicco. A. Branch with closed fruits. B. Detail of the abaxial surface of leaf blade. C. Detail showing a cross section of the closed fruit with an aborted seed. D. Gray shadows show the fruit shape and number of septa in T. caloneura (left) and T. manauara (right). A and C detail from Nee 42991 (NY01417188); B and C from Silva s/n (NY01417091). Image courtesy of the C.V. Starr Virtual Herbarium, New York Botanical Garden (http://bluegum.nybg.org/science/vh/).

FIGURE 2. Transversal sections of the petiole of Tovomita manauara (A–C) and T. caloneura (D–F). A. General overview of vascular system and secretory canals distribution across cortical region, black arrows showing secretory canals. B. Detail of vascular bundles; notes the absence of fibers around the vascular bundles. C. Detail of angular collenchyma (white arrow) and presence of druse. D. General overview of the vascular system and secretory canals distribution across cortical region, black arrows showing secretory canals. E. Detail of vascular bundles. F. Detail of the petiole, arrowheads showing idioblasts. co—cortex, col—collenchyma, vb—vascular bundles, ep— epidermis, xy—xylem, ph—phloem, sc—secretory canals, dr—druse.

FIGURE 3. Scanning electron micrographs (SEM) from the leaf blade of Tovomita manauara (A–C) and T. caloneura (D–F). A–B. Abaxial surface view. C. Detail of a stomata. D. Abaxial surface view. E. Detail of a stomata. F. Detail of a druse on the petiole. dr—druse, st—stomata.

FIGURE 4. Transversal sections of leaf blade of Tovomita manauara (A–B) and T. caloneura (C–E). A. Transverse section with general view, black arrows point to secretory canals, black arrowheads point to fibers. B. Detail of the vascular system and secretory canals (black arrow). C. Transverse section with general view. D. Vascular bundles in the general view. E. Transversal section of the leaf blade. mv— midvein, ms—mesophyll, ct—cuticle, xy—xylem, ph—phloem, pp—palisade parenchyma, sp—spongy parenchyma, ep—epidermis, vb – vascular bundles.