Margyricarpus microcarpus Funez, 2021

Funez, Luís A., Hassemer, Gustavo, Peroni, Nivaldo & Drechsler-Santos, Elisandro R., 2021, Two new species of Margyricarpus (Rosaceae, Sanguisorbeae) from high-elevation grasslands in southern Brazil, and other notes on the genus Margyricarpus, Phytotaxa 496 (3), pp. 281-293 : 285

1.2. Margyricarpus microcarpus Funez , sp. nov.

Differs from Margyricarpus pinnatus (Lam.) Kuntze by the fruits 2.0–2.5 × 1.0– 1.1 mm, endocarp obovoid, expanded in very small rounded projections of <1 mm, vs. fruits 3.8–4.2 × 1–2 mm, endocarp ellipsoid, with four longitudinal rows of thorny curved projections of 0.4–0.8 mm long.

Type: — BRAZIL. SANTA CATARINA: Bom Jardim da Serra, Parque Nacional de São Joaquim, Campos de Santa Bárbara , 24 February 2019, L. A. Funez et al. 8774 (holotype FURB-65014!). Figures 4–5 .

Perennial plants 15–45 cm tall, erect, with lignified branches; covered by the sheathing base of the petioles; densely villose above the sheaths, covered by white trichomes, glabrescent on the opposite side; leaf sheaths glabrous, 4.0– 4.2 mm long, with the main vein strongly impressed, stramineous, densely villous at the margin; petioles 0.2–0.5 mm, glabrous or glabrescent only in adaxial surface. Leaf blades imparipinnate, with 2–3 pairs of leaflets; leaflets 3–7 × 0.1–0.2 mm, narrow oblong, the apex acute–apiculate and the base obtuse truncate, the margin strongly revolute, glabrous on both sides, sessile; leaves of the main stems with petiole-rachis axis persistent, 6–7 mm long, stramineous, glabrous, curved down, and leaflets easily deciduous; leaves of the secondary stems with petiole-rachis axis shorter than 4 mm, the leaflets smaller than those of the main stems, crowded, persistent still at flowering time. Flowers solitary and axillary. Sepals 4, green, ca. 0.2 mm long, broad elliptic, acute, glabrous. Stamens 2, purplish, easily deciduous. Stigma flabellate. Fruits partially visible in the plant, each one covered by the hypanthium, 2.0–2.5 × 1.0– 1.1 mm, glabrous, fleshy, whitish-hyaline and rounded in vivo, endocarp obovoid, expanded in very small rounded projections of <1 mm, present in longitudinal rows, the basal portion forming a narrow beak of 0.2–0.4 mm long.

Etymology: —The specific epithet makes reference to the small size of the fruits of this species.

Distribution and habitat: —Known from a small area in Urubici and Bom Jardim da Serra municipalities, in Santa Catarina state, southern Brazil ( Figure 3 ). This species occurs in rocky outcrops and rocky soils along riverbanks and grasslands were found flowering during September to October, fruiting during December to February.

Conservation status: — Critically Endangered ( CR — B1,2 :a,b[iii,v]), according to the IUCN criteria ( IUCN 2012 , 2019 ). This species is only known from the type locality, where several individuals were observed, the majority of which along riverbanks. Although it occurs in environmentally protected area, Parque Nacional de São Joaquim, this conservation unit has suffered repeated attacks by politicians and ruralists who seek to detach large areas of the Park to establish farms, hydroelectric plants or wind farms .

Additional material examined (paratypes): — BRAZIL. SANTA CATARINA: Bom Jardim da Serra, 16 December 2018, L. A. Funez et al. 8487 (FURB-65020): Campos de Santa Bárbara. Parque Nacional de São Joaquim ; Urubici : Santa Bárbara , próximo ao alojamento. Parque Nacional de São Joaquim , 25 January 2019, L. A. Funez et al. 8619 (FURB-65004)

Notes: —This species resembles M. pinnatus , differing due the small size of the reproductive parts with sepals ca. 0.2 mm long and fruits 2.0–2.5 ×1.0– 1.1 mm, glabrous, fleshy, whitish-hyaline and rounded in vivo, endocarp obovoid, expanded in very small rounded projections of <1 mm, present in longitudinal rows vs. sepals 1.0–1.2 × 0.7–0.8 mm, fruits 3.8–4.1 × 1.8–2.0 mm, white and rounded in vivo, endocarp ellipsoid, with four longitudinal rows of thorny curved projections of 0.4–0.8 mm long. The habitat of M. microcarpus is rocky outcrops and riverbanks at high elevations. Sometimes M. microcarpus is sympatric with M. pinnatus , frequently on mixed populations.

Figures

FIGURE 3. Distribution map of Margyricarpus lanatus (green dot) and M. microcarpus (red dot).

FIGURE 4. Field photographs of Margyricarpus microcarpus. A. Detail of the flowers. B–C. Detail of the fruits. D. Dehydrated fruits, showing the endocarp sculpture. E. Detail of the stem and leaves. F. Habit and habitat.

FIGURE 5. Holotype of Margyricarpus microcarpus (L.A. Funez et al. 8774 FURB-65014). Copyright: Universidade Regional de Blumenau.