17. Piptolepis riparia Loeuille, Semir & Pirani (2019: 95). Type:— BRAZIL. Minas Gerais: São Gonçalo do Rio Preto, Parque Estadual do Rio Preto, margem do Córrego das Éguas, 8 February 2010, B. Loeuille et al. 516 (holotype: SPF! [SPF221000]; isotypes: BHCB!, K!, NY!, P!, RB!, UFP!, US!) (Fig. 3 J, 27 C–D).

Shrub 0.40–1 m tall, virgate, densely branched with long and arching branches. Stems slightly corrugated, puberulent, saffron, old stems rugose, becoming glabrescent, dark brown, leaf scars deltate. Leaves ericoid, ascending, sessile to subsessile, petiole (0–) 0.5–1.5 mm long, pad-like leaf sheath ligulate, 0.6–1.8 mm long; blade very narrowly elliptic to narrowly oblanceolate, 5–15 × 1.5–4 mm, apex subacute to obtuse, base attenuate, chartaceous, venation hyphodromous, midrib adaxially sunken, slightly concealed by indumentum, abaxially prominent, adaxial surface tomentulose, dark olive green to gray green, abaxially lanate, sage green, margins flat. Inflorescence in raceme, terminal at apex of branches, with leaf-like bracts at base of capitulum, 7–10 × 0.6–2.3 mm, apex subacute to obtuse, base attenuate. Capitula 2–10, sessile; involucre campanulate, 6–8 mm tall × 6.5–10 mm diam., 5–6 seriate; phyllaries persistent, scarious, glandular-punctate, outer phyllaries narrowly triangular, 3–4 × 0.2–1 mm, apex acute, lanate, stramineous, inner phyllaries lanceolate, 5–7 × 0.5–1.1 mm, apex subacute to obtuse, lanate only at apex, light green; receptacle fimbrillate. Florets 13–15; corolla lilac, glabrous, glandular-punctate, 8–9 mm long, corolla tube 4–5 × 0.5–1.5 mm, corolla lobes 3.4–3.8 × 0.5–0.9 mm, apex acute; anthers lilac, apical appendages acute; style shaft 7–11 mm long, pale lilac, glabrous throughout except for pubescent upper ca. 1 mm beneath style arms, style arms 2–2.2 mm long. Cypselae prismatic, 1.5–2 × 0.8–1.2 mm, 10-ribbed, glabrous, slightly glandular-punctate, light brown; pappus setae biseriate unequal, outer series 0.3–1.4 mm long, persistent, inner series 2.8–4 mm long, stramineous, subpaleaceous, serrulate, tapering towards the apex, deciduous.

Distribution and habitat: —Endemic to the Diamantina Plateau in the Espinhaço Range in the state of Minas Gerais, in São Gonçalo do Rio Preto (Fig. 10, 24). This species occurs in a quartzite rock outcrops in rocky river banks.

Conservation Status: — Loeuille et al. (2019) classified this species as Data Deficient (DD), since it was known only from the type material. Here, we recovered more population data and provide an update to the conservations status. This species is considered Least Concern (LC); it has an extent of occurrence (EOO) of 3.18 km 2 and an area of occupancy (AOO) of 12.000 km 2. The two known populations occur within protected areas at Parque Estadual do Rio Preto (Fig. 10) (Amorim & Bicalho 2022h).

Etymology: —The epithet refers to the habitat of the species, which was collected on a rocky river bank (Loeuille et al. 2019).

Phenology: —Flowering and fruiting specimens were found from March to June.

Notes: —This species is known from a few gatherings. Piptolepis riparia is recognized by its shrubby and densely branched habit with long and arching branches, narrowly elliptic to narrowly oblanceolate leaf blade with prominent midrib abaxially, 13–15 florets per capitulum, prismatic cypselae and unequal pappus series.

The species P. fulgens, P. monticola and P. oleaster occur in sympatry with P. riparia in Parque Estadual do Rio Preto; however, P. riparia differs from P. monticola and P. oleaster by its shrubby habit (vs. treelet), 2–10 florets per capitulum (vs. 15–23), prismatic cypselae (vs. cylindrical), unequal pappus series (vs. equal to subequal). It differs from P. fulgens by its very narrowly elliptic to narrowly oblanceolate leaves (vs. lanceolate), attenuate base (vs. rounded), tomentulose adaxial surface (vs. densely sericeous), flat margins (vs. revolute), phyllaries scarious at apex (vs. leaf-like) and prismatic cypselae (vs. turbinate). [For similar species see notes under P. ericoides, P. fulgens and P. elaeodes].

Representative Specimens Examined: — BRAZIL. Minas Gerais: São Gonçalo do Rio Preto, Parque Estadual do Rio Preto, próximo a prainha, [-18.116667°, -43.333333°], fl., fr. 13 June 1999, J. A. Lombardi 3054 (BHCB, MBM, US); ibid, [-18.116°, -43.345°], 790 m, fl., fr. 14 May 2012, C. Delfini 464 (BHCB, ESA, HUFU, RB, SPF); ibid, [-18.11525°, -43.3414444°], 768 m, fl., fr. 9 May 2019, J. B. Cândido 325 (UFP); ibid, [-18.11672222°, - 43.3407222°], 770 m, fl., fr. 9 May 2019, J. B. Cândido 326 (UFP); Parque Estadual do Rio Preto, trilha para a cachoeira do Criolo, [-18.145556°, -43.370556°], 900 m, fl., fr. 21 March 2016, G. Martinelli 19248 (ALCB, HUFU, RB); ibid, [-18.14561111°, -43.36658333°], 873 m, fl., fr. 24 May 2019, J. B. Cândido 380 (UFP); ibid, [-18.14575°, -43.36102777°], 851 m, fl., fr. 24 May 2019, J. B. Cândido 381 (UFP); ibid, [-18.1437777°, -43.35902777°], 831 m, fl., fr. 24 May 2019, J. B. Cândido 382 (UFP).