Sideroxylon obtusifolium T. D. Pennington 1990
Creators: name: Völtz, Rafael R.
name: Alves-Araújo, Anderson
name: Goldenberg, Renato
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Ericales
Sapotaceae
Sideroxylon
Sideroxylon obtusifolium

description: 7.1 Sideroxylon obtusifolium (Humboldt ex Roemer & Schultes 1819: 802) T.D. Pennington (1990: 113). Figure 26
Treelet. Trunk section cylindrical or slightly irregular, weakly buttressed or not; bark grayish-brown, fissured, fissure deep, short, V-shaped, oblique to slightly reticulate, ridges flattened or reticulate; slash light yellow-orange, tangential section with longitudinal streaks, not discoloured, with abundant latex. Stems with young shoots light brownish-yellow, soon grayish-brown, lenticellate, rough and scaling in thin scales, rounded, tomentose or puberulent at first, becoming glabrous when older. Petiole 3.0–9.0(–11.0) mm long, grooved, tomentose or puberulent at first, soon glabrous or pubescent at the base. Leaf blade chartaceous or thinly coriaceous, 1.5–5.5 × 1.0– 2.5 cm, oblanceolate, narrow-obovate, narrow-elliptic, elliptic or seldom wide-elliptic, apex obtuse, rounded or slightly retuse, base acute or cuneate, adaxial surface sericeous-tomentose at first, soon glabrous, but sometimes with sparse hairs on midrib, abaxial surface puberulent or glabrous, midrib sunken on the base turning flat at the apex on the adaxial surface, raised on the abaxial surface, secondaries 6–12 pairs, flat or slightly raised on the adaxial surface, slightly raised or seldom inconspicuous on the abaxial surface, tertiaries flat or slightly raised on the adaxial surface, flat or slightly raised or occasionally inconspicuous on the abaxial surface. Inflorescences 1–11-flowered. Pedicel 2.4–5.6 mm long, puberulent. Flowers whitish in vivo; sepals 2.2 mm long, elliptic, apex rounded, margin entire, abaxial surface glabrous or puberulent on the base, adaxial surface glabrous, with a broad glabrous marginal stripe; corolla 3.2–4.2 mm long, tube 1.2 mm long, lobes 2.0–3.0 mm long, median segment elliptic, apex truncate or rounded, lateral segments narrow-lanceolate, apex acute, slightly shorter than the median segment; filaments 1.2–2.3 mm long, glabrous, anthers 1.2–1.8 mm long, glabrous; staminodes 2.2–2.6 mm long, lanceolate, margin erose; ovary 0.9–1.2 mm long, ovoid, style 2.5–3.0 mm long, glabrous, stigma simple or slightly lobed. Fruit immature greenish, globose, calyx and style persistent.
Selected material: — BRAZIL. Paraná: Assaí, 4 November 1999, E.M. Francisco s.n. (FUEL 26601, UPCB). Jataizinho, 22 August 1998, E.H. Camargo s.n. (FUEL 25898, HUEFS). Leópolis, 21 May 1999, O.C. Pavão s.n. (FUEL 25899, INPA).
Additional examinated material: — BRAZIL. Rio Grande do Sul: Capão do Leão, 23 November 1986, J.A. Jarenkow 522 (MBM, UEC). Santa Catarina: Laguna, 27 September 2000 G.G. Hatschbach 27527 (MBM).
In Paraná Sideroxylon obtusifolium has been found only in its Northern portion, in riversides and alluvial plains or ocassionaly on drier hillsides, in Semideciduos Seasonal Forest between 365 and 670 m elev. Collected with flower buds in August and immature fruits in March, May and November. It can be recognized by the grayish-brown fissured bark, fissures deep, short, oblique to slightly reticulate, young shoots with leaves opposite or subopposite, soon alternate or fascicled in short shoots, the stems commonly spiny (the spine a sharp end of the branch), and the corolla divided to the base into three segments. The collections from Paraná belong to S. obtusifolium subsp. obtusifolium (according to Pennignton 1990), which differs from S. obtusifolium subsp. buxifolium (Roemer & Schultes 1819: 802) T.D. Pennington (1990: 113) by the leaves opposite to subopposite at first, becoming fascicled on short shoots (vs. opposite, no becoming fascicled in S. obtusifolium subsp. buxifolium), the leaves oblanceolate, narrow-obovate, narrow-elliptic, elliptic (the length-width ratio equal or more than 2:1) (vs. ovate or wide-ovate (the length-width ratio less than 2:1), and corolla 4.0– 4.5 mm long (vs. 3.9- 3.5 mm long), besides the distinct geographic occurrence. However, the specimens studied have corolla 3.2–4.2 mm long, causing an overlap with that described from S. obtusifolium subsp. buxifolium by Pennington (1990).
Conservation Status: —This species was listed as “Least concern” (LC) by CNCFlora (2018). In Paraná S. obtusifolium is irregularly distributed on alluvial plains in Semideciduous Seasonal Forest, and none of the individuals are in protected areas. The main problem to its conservation are the decline in the quality of habitat and habitat loss to agriculture or pastures.
description: Published as part of Völtz, Rafael R., Alves-Araújo, Anderson & Goldenberg, Renato, 2020, Native Species of Sapotaceae Juss. in Paraná, Brazil, pp. 224-276 in Phytotaxa 430 (4) on pages 270-271, DOI: 10.11646/phytotaxa.430.4.1, http://zenodo.org/record/13876096