Amorimia tumida R.F.Almeida & A.C.Marques, 2017
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publication ID |
https://doi.org/ 10.11646/phytotaxa.305.3.5 |
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DOI |
https://doi.org/10.5281/zenodo.13694911 |
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persistent identifier |
https://treatment.plazi.org/id/DF5C87DB-5756-FFDF-FF53-F8E6EAAEA038 |
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treatment provided by |
Felipe |
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scientific name |
Amorimia tumida R.F.Almeida & A.C.Marques |
| status |
sp. nov. |
Amorimia tumida R.F.Almeida & A.C.Marques View in CoL , sp. nov. ( Figs. 1–5 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 )
Type:— BRAZIL. Rio de Janeiro: Mun. Cardoso Moreira, Serra da Bandeira , 17 December 2013, fr., M. N. Coelho & I. G. Costa 2794 (Holotype: RB!; isotypes: CEPEC!, HUEFS!) .
Differs from Amorimia andersonii by its elliptic leaf blades, eglandular base, fewer secondary veins, secondary veins joining the primary vein in an acute angle, more obtuse in the apex; fewer flowers in the inflorescence; pedicel tumid in fruits; filaments entirely sericeous; styles entirely sericeous; samaras sericeous and metallic coloured.
Woody vine; stem sparsely sericeous to glabrous at age; stipules 0.5–0.6 mm long, triangular, epipetiolar, persistent to deciduous. Leaves opposite, reduced to bracts in the inflorescences; petioles 4.3–6.6 mm long, sparsely sericeous to glabrous, eglandular at apex; blades 4.0–9.5 × 2.1–5.1 cm, plane, elliptic, base obtuse, margin slightly revolute in sicco, apex acuminate, adaxially glabrous, abaxially sparsely sericeous to glabrescent at age, eglandular; midvein adaxially prominent, abaxially prominent, 8–9 pairs of secondary veins, arching 48–55°, opposite to subopposite, both sides impressed, reticulum impressed and conspicuous on both sides. Thyrses (pseudoracemes) axillary; main axis 8.45–9.75 cm long, cylindrical, striated, sericeous; cincinni 1-flowered, 6–8-cincinni, decussate; bracts 1.3–3.3 × 1.0– 1.6 mm, lanceolate, petiolate, conduplicate, deflexed, 1 pair of marginal glands near base, both sides sericeous; peduncle 11–20 × 0.7–1.0 mm, laterally flattened, sericeous; bracteoles 1.1–1.8 × 0.5–0.6 mm, oblong, sessile, conduplicate, inserted 2.5–4.0 mm below the apex of peduncles, subopposite, deflexed, eglandular, both sides sericeous. Flowers unknown; floral buds (fragments) 5.5–8.0 × 5.0–6.0 mm; pedicels (in fruits) 6.0–8.0 × 1.0– 1.5 mm, sericeous to glabrescent, tumid. Sepals (in fruit) 3.5–4.0 × 2.5–3.0 mm, narrowly oblong, apex obtuse to rounded, revolute at anthesis, both sides sericeous; glands 3.0–3.1 × 1.3–1.5 mm, greenish turning brown at age. Petals unknown. Stamens (persistent in young fruits) 10; filaments 1.8–2.0 × 0.5–0.7 mm, connate 1.0– 1.5 mm long at base, entirely sericeous on both sides; anthers unknown. Ovary unknown (probably sericeous); styles 3, cylindrical at base, cylindrical at apex, parallel at base and middle, apex apiculate, entirely sericeous; anterior style 2.0– 2.1 mm long; posterior styles 2.5–2.8 mm long; stigma lateral, crateriform. Samaras metallic green in vivo and metallic ocher in sicco; dorsal wing 10–15 × 5.0–6.0 mm, depressed ovate, margin entire, sericeous on both sides; lateral wings 1.6–2.3 × 1.8–3.0 cm, flabelliform, margin entire to sinuate, upper angle 15° and lower angle 55° from the nut, sericeous on both sides; nut narrowly ovoid, sericeous; areole 8.6–10.0 × 2.6–3.5 mm, narrowly ovoid. Seeds 6.1–9.0 × 3.5–6.5 mm, testa rugose with lateral crests; embryo ovoid, cotyledons folded.
Distribution, habitat and phenology: — Amorimia tumida is known only from semi-deciduous forests in northern Rio de Janeiro state ( Fig. 5 View FIGURE 5 ), fruiting in December.
Conservation status: —Despite recent efforts, we were unable to find A. tumida in its type locality on Northern state of Rio de Janeiro again. The collector of the type specimen did not record geographic coordinates for the specimen, and little was written in the specimen’s label regarding habitat and locality. Unfortunately, this species remains known by a single collection from semi-deciduous forests associated to rocky outcrops within the Atlantic Forest of Serra da Bandeira, northern Rio de Janeiro state. Thus, based on our findings this species should be regarded as Data Deficient (DD).
Etymology: —The epithet makes reference to the species thickened fruiting pedicels, a unique feature in the genus.
Leaf anatomy: — Amorimia tumida and A. andersonii are quite similar in their leaf anatomy (compare Fig. 3a–b View FIGURE 3 with Fig. 3c–d View FIGURE 3 ). In the distal third, the petioles of both species show thin-walled cells in the epidermis of both sides ( Fig. 3e, g View FIGURE 3 ). In A. tumida , a sub-epidermal layer similar to the epidermis is observed in the entire petiole, but cells here are larger than in the epidermis ( Fig. 3e View FIGURE 3 ); the sub-epidermal layer is undifferentiated in A. andersonii ( Fig. 3g View FIGURE 3 ). A slightly thickened collenchyma occurs adjacent to the epidermis and throughout the petiole ( Fig. 3a, e View FIGURE 3 and Fig. 3c, g View FIGURE 3 ). This is more evident in A. andersonii . In transversal section, the main vascular unit shows secondary growth and forms an open arch with non-convoluted extremities arranged collaterally ( Fig. 3a, c, f, h View FIGURE 3 ). Two accessory vascular bundles are arranged adaxially at each side of the main vascular unit ( Fig. 3a, c View FIGURE 3 ).
The leaf blade of both species is hypostomatic ( Fig. 3i, l View FIGURE 3 ) with paracytic stomata ( Fig. 3j, m View FIGURE 3 ) occurring at the same level of the ordinary epidermal cells ( Fig. 3i, l View FIGURE 3 ). The cuticle is thin and cuticular flanges ( Fig. 3k, n View FIGURE 3 ) can be seen throughout the leaf blade extension. The epidermis is single-layered and shows thin cell walls. In transverse section, the epidermal cells are larger on the adaxial face than on the abaxial one ( Fig. 3i, l View FIGURE 3 ). Furthermore, the cells are larger on the semi-blade and smaller on the primary vein on both sides ( Fig. 3b, d View FIGURE 3 ). At the blade margin in A. andersonii , it is also possible to notice a subepidermal layer similar to the epidermis ( Fig. 3o, p View FIGURE 3 ). The leaf blade possesses collenchyma adaxially and abaxially in the midrib ( Fig. 3b, d View FIGURE 3 ) and has a dorsiventral mesophyll ( Fig. 3i, l, o, p View FIGURE 3 ), with a single-layered palisade parenchyma that extends all the way to the margin, in A. tumida ( Fig. 3o View FIGURE 3 ); and ending before the margin in A. andersonii ( Fig. 3p View FIGURE 3 ). Idioblasts containing druses occur in the palisade parenchyma ( Fig. 3i, l View FIGURE 3 ) of both species. The margin is revolute in A. andersonii , showing a fiber block near the epidermis, separated by few layers of subepidermal parenchyma (compare Fig. 3o View FIGURE 3 and Fig. 3p View FIGURE 3 ). The spongy parenchyma is composed of braciform cells and idioblasts containing druses ( Fig. 3q, s View FIGURE 3 ). The midvein shows a secondary growth and with the same collateral disposition observed in the petiole ( Fig. 3b–d View FIGURE 3 ). Fibers contour the primary vein with more layers of fiber occurring abaxially ( Fig. 3b, d View FIGURE 3 ). Glands are present on the abaxial face of leaf blades for both species. The epidermis of these glands is composed by palisade cells and the subglandular parenchyma is different of the adjacent tissues, showing smaller, denser and juxtaposed cells ( Fig. 3r, t View FIGURE 3 ).
Leaf architecture: —In A. tumida the leaf blade shows a camptodromous-brochidodromous venation pattern, with a straight and non-ramified primary vein ( Fig. 4a View FIGURE 4 ), as we can also see in A. andersonii ( Fig. 4b View FIGURE 4 ). Secondary veins are of moderate caliber and non-ramified ( Fig. 4a, b View FIGURE 4 ). In the median region of the leaf blade, the angle of divergence between the secondary veins and the primary vein is acute in A. tumida ( Fig. 4a View FIGURE 4 ), and straight in A. andersonii ( Fig. 4b View FIGURE 4 ). This angle is more obtuse in distal secondary veins than in proximal ones in A. tumida ( Fig. 4a View FIGURE 4 ), while A. andersonii divergence angles are uniform ( Fig. 4b View FIGURE 4 ). The course of the secondary veins is uniformly curved, and join the superadjacent secondary vein in a right angle in A. tumida ( Fig. 4a View FIGURE 4 ), and abruptly curves joining the superadjacent secondary veins in acute angle in A. andersonii ( Fig. 4b View FIGURE 4 ). The last marginal veins form arches on both species ( Fig. 4c, d View FIGURE 4 ). Areoles are imperfect in shape, randomly arranged, and predominantly quadrangular in both species ( Fig. 4c, g View FIGURE 4 ). Veinlets vary from simple and linear to branched ( Fig. 4d, h View FIGURE 4 ) in both species.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.