Brazil. Pará: Floresta Estadual de Trombetas, comunidade Jaramacaru, cachoeira do Rio Jaramacaru; 9 Jun. 2019; D.C. Zappi, C.O. Andrino, R.G. Barbosa-Silva & C. Maurity 4853 (holotype MG; isotype SPF).

Figure 1. 

Distribution map of the new species of Utricularia in the Amazon. On the left map, the main rivers of the hydrographic basin of the region and which cross the FLOTA Trombetas (highlighted in green). The map to the right shows the records of Utricularia ariramba (squares) and Utricularia jaramacaru (triangle), which are near the FLOTA limits, as well the as threats to the area, including recent fires, full deforestation, and selective deforestation of timber species.

Utricularia ariramba belongs to U. sect Aranella (Barnhart) P.Taylor, being most similar to U. costata P.Taylor, but distinguished by its taller inflorescences 5.3–12.0 cm long (vs. 2–7 cm long), the less conspicuous nerves on the calyx lobes, the upper calyx lobe with acute apex (vs. obtuse and obscurely denticulate), spur swollen and dorsiventrally flattened in the apical 2/3 (vs. cylindrical with apex narrowing towards the tip), lower corolla lip trapezoid with margin entire or finely denticulate (vs. transversely oblong with margin entire or shallowly 3-lobed), and upper corolla lip narrowly ovate with acute apex (vs. ovate, with apex rounded or subacute).

Small-sized, probably annual, terrestrial. Rhizoids few, capillary, from the peduncle base, sometimes also from the basalmost scales, with short papillose branches, up to 0.8 mm long, 0.1–0.2 mm in diameter. Stolons few, capillary, terete, sparsely branched, a few cms long, c. 0.1 mm in diameter. Leaves few, on the stolons, petiolate, lamina narrowly linear, 1-nerved, up to 5 mm long, 0.1–0.2 mm wide. Traps numerous on the leaves and stolons, ovoid, stalked, 0.15–0.20 mm long, the mouth lateral with a single, conical, dorsal appendage and a longer, deeply bifid, ventral appendage. Inflorescence a bracteose raceme, erect, simple, solitary, 53–120 mm long; peduncle capillary, terete, glabrous, 0.2–0.3 mm in diameter, reddish-green. Scales, bracts, and bracteoles basifixed and single-nerved. Scales few to numerous, ovate-deltoid to ovate, with apex acute, 0.5–1.0 mm long. Bracts ovate-deltoid to lanceolate, with apex acute, 0.7–1.1 mm long. Bracteoles subulate, slightly shorter than the bract, with apex acute, 0.7–1.0 mm long. Flowers 1–6; pedicel ascending, filiform, terete, 0.5–2 mm long, c. 0.1 mm in diameter. Calyx lobes unequal, glabrous, with 9–13 very conspicuous, simple, parallel, raised nerves, green to greenish-red in color; upper lobe ovate with apex acute, convex, 2.0–2.5 × 1.2–1.5 mm; lower lobe ovate, convex, with apex bifid, 2.6–3.3 × 1.5–2.0 mm. Corolla white or lavender, with the lower lip with a yellow-orange mark on the top and violet nerves on the limb, 8–11 mm long, finely papillose; upper lip narrowly ovate 4.0–5.5 × 2–3 mm, apex acute, lateral margins retroflexed, basal sac with ciliated rim; lower lip limb trapezoid, margin entire or finely denticulate, straight or retroflexed, shallowly 3 lobed, 3–5 × 3–7 mm, palate with papillose rim; spur conical, swollen and dorsoventrally flattened in the apical 2/3, the apex truncate to sub-acute, projected to the front, longer than and +/- parallel to the lower lip, 5.0–6.1 × 2.2–3.1 mm, papillose and finely ciliated. Filaments curved, c. 0.8 mm long, the anther thecae sub-distinct, anther c. 0.70 × 0.25 mm. Ovary globose, 0.5 mm long; style short, c. 0.2 mm long; stigma bilabiate, lower lip semicircular, 0.3 mm wide, upper lip broadly deltoid. Capsule and seeds not seen.

The epithet “ariramba” is a name in apposition, referring to the Campos de Ariramba, where this new species was discovered. The word “ariramba” comes from the Tupi language “uarirámba” and refers to the birds of the Galbulidae family, which are commonly found in the area.

The species was collected in full bloom at the end of the rainy season, in May and June.

So far, only known from two subpopulations at the margins of the Jaramacaru River, in the Campos do Ariramba region. The area lies within the conservation unit of the Floresta Estadual de Trombetas (FLOTA Trombetas), in western Pará state, N Brazil. The species occurs on white sandy soils on a flat sandstone outcrop in campinarana (white sand vegetation).

Vulnerable: VU D2. Utricularia ariramba is known from only three collections, one of which was made over 60 years ago and lacked georeferenced data. The recently collected specimens were found ca. 3 km distant from each other, near the border of the FLOTA Trombetas (Fig. 1). Areas under active deforestation were observed just outside the conservation unit (Fig. 1), and during the fieldwork activities in 2019, fire was observed in a waterfall 6 km upriver from the Jaramacaru community, suggesting environmental disturbance generated by cattle farming and other human activities. In fact, large areas were recently impacted by fires less than 1 km away from the subpopulations (Fig. 1; data from Assis et al. 2019). In addition, the site is sought by tourists from nearby municipalities because of the Jaramacaru waterfall, therefore leading to negative anthropogenic impact on the populations. Although the Campos do Ariramba are a botanically unexplored region with vast areas of habitats similar to those where the species was collected and the population size has not been ascertained, the available data suggests that the species is restricted to a few locations. An AOO of just 8 km² was calculated for this species, and we observed threats that might impact its habitat quality and AOO in the short term and lead to a reduction in population size and area of occupancy. Therefore, we assign the species to the Vulnerable category based on criterion D2 of IUCN (2012).

Utricularia ariramba is placed in U. sect. Aranella based on its characteristic trap morphology (a single subulate dorsal appendage and a deeply bifid ventral appendage), and the presence of a clearly defined basal sac in the upper corolla lip.

Utricularia ariramba is the eleventh species of Utricularia sect. Aranella (Taylor 1989; Fleischmann and Rivadavia 2009), a section almost completely endemic to tropical South America, with a single species (U. simulans Pilger) extending to Central America, the Caribbean and tropical Africa (Taylor 1989).

Utricularia ariramba is most similar to U. costata, sharing similar bract and bracteole morphology, and the lavender (to white) corolla with darker violet venation in the lower lobe. It is distinguished by the relatively larger inflorescences 5.3–12.0 cm tall (vs. 2–7 cm tall), the less prominent nerves on the calyx lobes, the upper calyx lobe with acute apex (vs. obtuse and obscurely denticulate), the swollen spur in the apical 2/3 (vs. apex tapering towards the tip), the lower corolla lip trapezoid with margin entire or finely denticulate (vs. transversely oblong with margin entire or shallowly 3-lobed), and the upper corolla lip narrowly ovate with acute apex (vs. ovate, with apex rounded or subacute). For photos of U. costata, see Costa et al. (2016: 11, Fig. 3D, E) and Mota and Zappi (2018: 126, Fig. 3a–c).

Utricularia costata occurs in Venezuela and Brazil, where it is recorded from the states of Roraima, Pará, Mato Grosso, Goiás, Bahia, Sergipe and Alagoas (Taylor 1989, 1999; Fleischmann and Rivadavia 2009; Carregosa and Costa 2014; Costa et al. 2016; Guedes et al. 2018; Flora do Brasil 2020 under construction). In Pará, the species is recorded from the southeast region of the state, in the Serra dos Carajás (Mota and Zappi 2018).

Variation in corolla color and spur morphology was observed in the studied specimens of U. ariramba, where it varies from white to lavender, and the different corolla colors are associated with different spur shapes: both variants show a dorsoventrally flattened spur in the apical 2/3, but the white variant (represented by the type specimen) shows a higher degree of flattening, a ventral concavity (Fig. 2c), and a truncate apex (Fig. 3a), while the lavender variant (represented by the paratypes) has a spur only slightly flattened, without the concavity, and with an acute apex (Figs 2i, 3b, d). Furthermore, in the white morphotype, the apex of the lower corolla lip is reflexed (Figs 2h, 3a). Despite these differences in corolla color and shape, both morphotypes are considered conspecific as the specimens share similar morphology in all other characters. Variation in corolla color and shape is common in other species of U. sect. Aranella, as exemplified by intra-populational variation observed in U. laciniata A.St.-Hil. & Girard and U. purpureocaerulea A.St.-Hil. & Girard in several areas across their range (PMG pers. obs.), as well as in lavender- and white-flowered color morphs of U. blanchetii A.DC. in the Chapada Diamantina (Taylor 1989; Rivadavia 2000).

Figure 2. 

Utricularia ariramba a, b habit, in flower c base of plant with stolons, rhizoids, and peduncle base d part of stolon, with rhizoids, and leaves with traps e utricle, side view f scale g, h flower of the white morphotype in anterior (g) and side (h) view i, j flower of the lavender morphotype in anterior (i) and side (j) view k flower of the white morphotype in posterior view l upper lip of the corolla, androecium, and gynoecium m stamen n pistil a, c–h, k–n based on the holotype; b, i, j based on C.O. Andrino 560. Illustrations by João Silveira.

Figure 3. 

Utricularia ariramba a inflorescence apex with flowers and bud of the white corolla morphotype, showing the reflexed apex of lower corolla lip b flowers of the lavender corolla morphotype, with a calyx of a developing fruit to the left c flower of the white corolla morphotype in posterior view, showing the calyx lobes and the concavity in the ventral portion of the spur d flowers of the lavender corolla morphotype e inflorescence apex of the white corolla morphotype showing variation in spur morphology.

Seeds were not available for study, however, Taylor (1989: 237) notes that seed morphology is rather uniform in U. sect. Aranella, hence not having great taxonomic significance (compared to other sections of the genus, where some species might be identified by a single seed grain alone; Taylor 1964, 1989).

(paratypes). Brazil • Pará; [Óbidos]; Campo do Jamaracarú [sic], perto do barracão, região do Ariramba; 26 May 1957; G.A. Black, W. Egler, P. Cavalcante & A. Silva 57-19633 (IAN 95750) • Óbidos; FLOTA Trombetas, comunidade Jaramacaru; 10 Jun. 2019; C.O. Andrino 560 (MG, SPF).

Brazil. Pará: Óbidos; Floresta Estadual de Trombetas, Ariramba, Rio Jaramacaru; 10 Jun. 2019; C.O. Andrino, R.G. Barbosa-Silva, D.C. Zappi & C. Maurity 559 (holotype MG; isotypes M, SPF).

Figure 4. 

Utricularia jaramacaru a habit, in flower b base of plant with stolons with traps, rhizoids, leaves with traps, and peduncle base c leave with traps d utricle, side view e scale f base of the pedicel, and bract g flower, in anterior h flower, in posterior view i flower, in lateral view j upper lip of the corolla k stamens l pistil m fruit n seed. All based on the holotype. Illustrations by João Silveira.

Utricularia jaramacaru belongs to U. sect. Setiscapella (Barnhart) P.Taylor but is distinct from all other members of this section by the traps with reduced, denticulate appendages (vs. subulate, branched), white corolla (vs. yellow or lilac), the upper corolla lip with bilobate apex (vs. obtuse, rounded, truncate or retuse), and the lower corolla lip narrowly rhombic (vs. cuneate, trullate, rhombic to very broadly rhombic in outline).

Small-sized, probably annual, terrestrial. Rhizoids 2–4, from the base of peduncle, terete, with short papillose branches, up to 1 cm long, c. 0.25 mm in diameter. Stolons numerous, capillary, sparsely branched, up to 1 cm long (in the available material), up to 0.1 mm in diameter. Leaves numerous, at the base of the peduncle and on the stolons, lamina narrowly linear, simple, the base narrowing gradually into a short petiole, apex obtuse to acute, green to reddish, 1-nerved, 2–6 × 0.2–0.5 mm. Traps numerous on the stolons and leaves, ovate, stalked, 0.1–0.2 mm long, the mouth lateral with two dorsal and very short denticulate, simple appendages. Inflorescence a bracteose raceme, erect, solitary, 60–130 mm tall. Peduncle capillary, terete, simple or eventually laterally simple-branched, glabrous, 0.2–0.3 mm in diameter, wine red. Scales numerous, peltate, ovate to narrowly ovate, inferior apex rounded to obtuse, superior apex acute, 0.5–0.9 mm long, similar to the bracts. Bracts ovate, basisolute, peltate, 0.5–0.7 × 0.4–0.5 mm, amplexicaul, the inferior apex rounded, the superior apex rounded to obtuse. Bracteoles absent. Flowers 4–13, the rhachis elongate, flexuous, without sterile bracts; pedicels ascending, capillary, terete, 3–9 mm long (longer towards the base of the inflorescence), pedicels with a mucilage droplet at their base in living specimens. Calyx lobes unequal, glabrous, nerves inconspicuous, simple, not extending to the margin; upper lobe ovate, with apex obtuse, convex, 0.9–1.1 mm long in flower, up to 1.3 mm in fruit; lower lobe obovate, with apex emarginate to rounded, convex, equal in length with the upper lobe in flower, slightly longer in fruit, up to 1.7 mm in fruit. Corolla 5 mm long, lower lip white with a pale yellow mark on the gibbose palate, spur pale yellow, upper lip pale yellow with reddish marks; upper lip oblong with apex bilobed, the basal sac with an eglandular pubescent marginal rim, the pubescence spreading towards the apex, c. 1.5 mm long; lower lip limb narrowly rhombic in outline, the base with a very prominent bilobed swelling, the apex 3-lobed, 0.3–4.5 mm; palate pubescent; spur cylindrical, apex rounded, equal to or slightly longer or shorter than the lower lip, 0.35–0.40 mm long. Filaments curved, 0.8–1.0 mm long, the anther thecae sub-distinct, anther 0.4–0.5 mm long. Ovary globose, 0.8–0.9 mm long; style very short; stigma lower lip nearly circular, upper lip obsolete. Capsule globose, c. 1.2 mm in diam., shorter than the calyx lobes, dehiscing by an elliptic ventral pore. Seeds obovoid to angulate-ellipsoid, 0.20–0.25 mm long, 0.13–0.20 mm wide, testa cells c. 0.01 mm wide, elongate, anticlinal boundaries deeply sunken and more or less straight, periclinal walls convex, smooth.

The epithet “jaramacaru” is a noun in apposition (hence it is invariant), referring to the Jaramacarú river, where the new species was discovered. “Jaramacarú” comes from the Tupi language “iamandakarú”, referring to species of the genus Cereus Mill. (Cactaceae). However, no cactus of this genus was located during the field trip undertaken by COA, RGBS, and DCZ in 2019.

Utricularia jaramacaru was collected with flowers in April, May, and June.

So far, only known from two very close localities near the Jaramacaru waterfall, in the Campos do Ariramba, part of the FLOTA Trombetas, western Pará, N Brazil. The species occurs on white sandy soils with outcrops of sandstone, in campinarana vegetation.

Vulnerable: VU D2. Similarly to that described for U. ariramba, U. jaramacaru is known from only two localities (AOO=8 km²) near the limits of FLOTA Trombetas and the threats the populations are subject to are fully explained in the above species. Therefore, based on available data, U. jaramacaru is to be assigned to the category of Vulnerable based on criterion D2 of IUCN (2012).

The basisolute, peltate scales and bracts, and the calyx and seed morphology (Figs 4–6) undoubtedly place this species in U. sect. Setiscapella, representing the tenth species of the section (following the species circumscriptions of Taylor 1989). However, based on morphology alone, it is not possible to assign the closest affinity of U. jaramacaru, as it bears several apomorphic characteristics, most remarkably regarding its trap and corolla morphology.

Figure 5. 

Utricularia jaramacaru a inflorescence apex with open flowers and bud b detail of inflorescence apex showing mucilage droplet in the axil of a pedicel c inflorescence apex with a flower in posterior view, highlighting the calyx (c1) d flower in anterior view; e, peduncle bases with stolons and leaves.

Figure 6. 

SEM microphotographs of seeds of Utricularia jaramacaru at 420× magnification, in dorsal, lateral and oblique view (from the holotype).

Up to now, U. sect. Setiscapella was composed of nine species (Taylor 1989), of which eight have yellow corollas (regarding the phylogenetic switch from lilac to yellow corolla color in Utricularia and Genlisea, see Fleischmann et al. 2010). One exception in terms of color is U. physoceras P.Taylor, also endemic to the state of Pará, but with larger (7–10 mm long vs. 5 mm) pink to lilac corolla. The whitish corolla of U. jaramacaru is, therefore, a second exception among the species of the section. Utricularia physoceras also shares the short spur with rounded apex with U. jaramacaru and similar seed morphology. Utricularia physoceras occurs in the cangas (ferruginous campo rupestre) of the Serra dos Carajás (Taylor 1989; Mota and Zappi 2018; Giulietti et al. 2019), distant ca. 815 km to the southeast from the area where U. jaramacaru was collected. For photos of U. physoceras, see Mota and Zappi (2018: 129, Fig. 4a–e) and Giulietti et al. (2019: 369, fig. 7 bottom three images).

Traps of U. jaramacaru are unlike any other species of U. sect. Setiscapella in that the appendages are reduced to two denticulate structures (Fig. 4d). All other species of the section bear subulate or filiform appendages near the trap door that are sparsely to copiously branched. Reduced appendages are found in different sections of Utricularia, which suggests it is a homoplastic character in the genus. Taylor (1989) enumerates a few species with reduced trap appendages, such as U. cornuta Michx. and U. juncea Vahl (both of U. sect. Stomoisia (Raf.) Komiya), U. nana A.St.-Hil. & Girard (U. sect. Benjaminia P.Taylor), U. guyanensis A.DC. (U. sect. Stylotheca A.DC.) and U. viscosa Spruce ex Oliv. (U. sect. Sprucea P.Taylor), all presenting only a small prolongation of the body of the trap on the dorsal side of the door.

The presence of a droplet of mucilage at the insertion of the pedicel in the peduncle (Fig. 5b) is shared with U. flaccida, U. nigrescens Sylvén and U. pusilla Vahl (P.M. Gonella and A. Fleischmann, pers. obs.), and its function remains unclear.

(paratypes). Brazil • Pará; [Óbidos]; Rio Jaramacaru, entre o acampamento e a cachoeira; 26 May 1957; G.A. Black, W. Egler, P. Cavalcante & A. Silva 57-19500 (IAN 95620) • ibid.; trilha após a ponte do rio Jamaracaru [sic], em direção à cachoeira; 01°10'12.99"S, 055°41'50.69"W; 80 m; 27 Apr. 2018; J.A. Siqueira Filho 4112 (HVASF 23703).