Arrojadoa bahiensis subsp. minutiflora Gonzaga & Oliveira-Pereira, 2025

Gonzaga, Diego Rafael & Pereira, Fabricio De Oliveira, 2025, Arrojadoa bahiensis subsp. minutiflora (Cactaceae, Cactoideae), a new subspecies from the Brazilian flora, Phytotaxa 684 (1), pp. 129-134 : 130-132

Arrojadoa bahiensis subsp. minutiflora Gonzaga & Oliveira-Pereira subsp. nov.

( Figs. 1–2 ).

Type:— BRAZIL. Bahia: Piatã, Chapada Diamantina , Serra de Santana , 06 August 2019, fl. and fr., F.O.Pereira 192 & R.Goloni (holotype UFG 73439 !).

Diagnosis:— Arrojadoa bahiensis subsp. minutiflora differs from A. bahiensis subsp. bahiensis ( Braun & Esteves Pereira 1993: 16) Taylor & Eggli (1993: 98) by the smaller size flowers (13.13–16.30 × 2.5 mm vs. 32.94 × 7.64 mm), cephalium undifferentiated distal flowering region (apical and lateral in subsp. bahiensis ), colour of flowers (light pink in outside part, white in inner part vs. strong pink flowers in outside external part), style length (10.13–11.23 mm vs. 25–28 mm long), colour of mature fruit (light pink to white vs. pink to reddish), shape and length of fruit (ovoid to piriform, 9.80–12.99 mm long vs. obovoid, 20.22–23 mm long), length of central spines (15.00– 18.44 mm vs. 22.35–33.00 mm).

Description:—Rupicolous, subglobose to columnar plants, 15–70 cm hight, branched at base, lonely, erect, green cladodes, c. 4.89 cm diameter., ribs 15–18, in-depth 7.04–10.10 mm; areoles 2.04–2.53 mm diameter, spaced c. 3 mm apart; cephalium undifferentiated distal flowering region (apical and lateral), spines, slightly flexible, brownish to reddish, white to yellowish trichomes at the base of the spines, 3.15–12.10 mm long., the radial 9–11, 2.96–6.35 × 0.26–0.30 mm, central 3–4, 11.74–13.60 × 0.30–0.32 mm, upper central spines 17.12–18.44 × 0.30–0.34 mm, up to 11–13 per areole. Light pink floral buds, naked. Flowers externally light pink, internally white, 1.31–1.63 × 0.38–0.42 cm, flower-tube naked, pink, pericarpel naked, ovoid, ca. 3–4 × 3.0 mm, nectar-chamber present, ca. 3 × 3 mm, perianth-segments c. 20, the external 1.5–2.0 × 1.5 mm, fleshy, elliptical, papillose, acuminate apex, the internal 3.36– 4.51 × 0.92–1.03 mm., delicated, lanceolate, ciliated, narrowed base and widened apex, stamens c. 97, in a continuous series, filaments 2–4 mm long, style 10.13–11.23 × 0.49 mm, stigma-lobes 4, lobes 1 mm long. Fruit 9.80–12.99 × 7.28–7.65 mm, ovoid to piriform, light pink to white mature, perianth-segments persistent, funicular pulp white and translucent, reminiscent base of the deepened flower. Seeds cochleariform, black, 1.29–1.48 × 0.85–1.19 mm, 0.60–0.94 thickness, warty, bright.

Etymology: —The specific epithet refers to the cactus having flowers and fruits that are smaller than the autonym subspecies.

Phenology and ecology: —Flowering time is August in wild, whereas in cultivation flowers occur from the near April and May to September. Flowers begin to open in the late afternoon, and close early the next morning, and last only one night. Fruiting occurs in mid-June. In the wild, hummingbirds have been observed visiting flowers, and in cultivation, hummingbirds and native stingless bees have been observed.

Distribution and habitat: — Arrojadoa bahiensis subsp. minutiflora is represented by a single population with a smaller number of individuals, distributed in low vegetation, along approximately 3 km of a white rock mountain range (sandstone), at elevation of 1200–1600 m a.s.l. in Piatã municipality, Bahia state, Chapada Diamantina in in the northern portion of Espinhaço Range. The vegetation occurring in this place is “Campo Rupestre”, Caatinga Domain. This population is sympatric with other cactus species such as Micranthocereus purpureus ( Gürke 1908: 86) Ritter (1968: 157) , A. luetzelburgii ( Vaupel 1923: 57) N.P.Taylor (2023: 1002) , while A. bahiensis subsp. bahiensis does not occur in this area.

Conservation status:— According to the IUCN criteria (2017), Arrojadoa bahiensis subsp. minutiflora is here assessed as Data Deficient (DD). In fact, since it is known only from one collection and from a single population, we think that other plants/populations could be found in different localities. Fire is the main threat to the specimens.

Additional material examined:— BRAZIL. Bahia, Piatã, Serra de Santana , 29 September 2021, fr., Zappi et al. 5294 (paratype, UB!).

Figures

FIGURE 1. Arrojadoa bahiensis subsp. minutiflora. A. Cactus habit. B. Areole with spines in detail. C. General habit. D. Flower in lateral view. E. View of flower interior. F. Flower in frontal view. G. Immature fruit in external view. H. Immature fruit in internal view. I. Comparison between fruits: right Arrojadoa bahiensis subsp. bahiensis and left this new subsp. Mature fruit in external view. J. Mature fruit in internal view with pulp. Photos by F.Oliveira-Pereira.

FIGURE 2. Map of the location of occurrence and record of Arrojadoa bahiensis subsp. minutiflora.