Stigmatodon carioca Manh

Manh, Vitor da Cunha, Couto, Dayvid Rodrigues, Salgueiro, Fabiano & Costa, Andrea Ferreira da, 2025, Morphological and Genetic Evidence for the Stigmatodon goniorachis Complex (Tillandsioideae, Bromeliaceae) Reveals a New Species on Inselbergs in the Brazilian Atlantic Forest, Systematic Botany (Basel, Switzerland) 49 (4), pp. 673-694 : 680-684

Stigmatodon carioca Manh ~ aes, D.R.Couto & A.F.Costa sp. nov. TYPE: BRAZIL. Rio de Janeiro, Rio de Janeiro, Natural Monument of the P ~ ao de Açucar and Urca Hills, P ~ ao de Açucar, on vertical slopes, 22 5790299S, 43 0991699W, 190 m elevation, 15 Aug 2007, C.R.P. França s.n. (holotype, R 212865).

Diagnosis — Stigmatodon carioca is morphologically similar to S. goniorachis (Baker) Leme, G.K.Br. & Barfuss , differing in the revolute leaf blade margins (vs. convolute), with trichomes forming white crossbands on both surfaces (vs. trichomes not forming white crossbands); inflorescence erect to suberect (vs. patent to pendulous), with peduncle suberect to arching (vs. patent to strongly curved), petals with apex obtuse and emarginate (vs. broadly rounded and emarginate); longer anthers (12–13 mm vs. 8.2–9.7 mm long); and longer style (26–28 mm vs. 22–23.5 mm long).

Plant rupicolous, 40–59 cm tall when flowering, propagating by numerous basal buds on the stem and axillary between the leaf blades. Leaves 15–47 in number, rosulate, thickly coriaceous, forming a funnelform rosette; sheath oblong to elliptic, 8.8–14.5 3 6.2–8.6 cm, dark brown, densely castaneous lepidote on both sides; blade triangular to narrowtriangular, apex long-acuminate, recurved, margins revolute, 16.8–30 3 1.7–3.7 cm, dark green, densely white-lepidote on both sides, trichomes forming white crossbands across the entire width of the leaf blade. Inflorescence simple, erect to suberect, ascending to apex, 12.4–24 cm long, 11–23 flowered; peduncle suberect to arched, 18.6–43.5 cm long, 0.3–0.5 cm in diameter, green, glabrous; peduncle bracts basal subfoliaceous, upper bracts elliptic, apex acute-apiculated, recurved in upper bracts, 2.0–3.3 3 1.2–2 cm, distinctly shorter than internodes, sparsely lepidote on abaxial side, erect, green at base with vinous apex or completely dark-vinaceous; main axis smooth at anthesis, green, glabrous, internodes 21–35 mm long; floral bracts ovate to suborbiculate, apex obtuse, 21–28 3 18–29 mm, distinctly shorter than sepals, sparsely and inconspicuously lepidote, ecarinate, secund with flowers before and at anthesis, coriaceous, smooth at anthesis, green with vinaceous apex or completely vinaceous. Flowers 35–46 mm long, nocturnal, with garlic scent, producing translucent mucilage, secund at anthesis; pedicel 0.4–0.7 cm long, 0.43–0.62 cm in diameter, green, glabrous; sepals elliptic to ovate, obtuse apex, 20–28 3 13–18 mm, green, glabrous, thick coriaceous near base, margin membranous; petals obovate to broad-elliptic, with apex obtuse and emarginate, recurved near tip, 30–38 3 14–21 mm, white, bearing 2 appendages at base; appendages 13 3 3 mm, obovate, basally adnate to petals for 8 mm, apex irregularly bidentate; corolla campanulate; filaments free, complanate, 36 3 2 mm, white; anthers 1.2–1.3 cm long, dorsifixed near base, base bilobed, apex obtuse, arranged three on each lateral side of corolla at anthesis; pistil equaling or exceeding stamens, 14–21 mm long; ovary superior, 5.8–6.2 mm long; ovules caudate; style green, 2.6–2.8 cm long; stigma tubo-laciniate type, denticulate at margins, 1.5–1.8 mm in diameter, green. Fruit capsules ellipsoid, brown, apex apiculate, 37 mm long; seed fusiform, ca. 4.5 3 1.0 mm, brown; basal coma ca. 20 mm long, beige; apical coma ca. 1 mm long, light brown. Figures 8 , 9 .

Additional Material Examined — Brazil. — RIO DE JANEIRO: Rio de Janeiro , P ~ ao de Açucar, vegetating on the vertical side of the inselberg, south side, 15 Aug 2007, fl., fr., C. R. P. França 24 ( R) ; Ibidem , 24 Nov 2017, fl. V. C. Manh ~ aes 733 ( R) ; Morro da Urca , 25 Oct 2013, fl.,fr., D. R. Couto 2378 & R. Moura ( R) ; Chacrinha State Park , vegetating on the vertical side of the inselberg, south side, 25 Feb 2015, fl., fr., D. R. Couto 3074 & L. I. T. Cardoso ( R) ; 21 Mar 2018, fl. V. C. Manh ~ aes 805 ( R) .

Phenology —Collected with flowers between October and March, bearing fruit between January and April.

Distribution and Habitat — Stigmatodon carioca is an hyperepilithic species, living on vertical granitic walls of the coastal inselbergs located in metropolitan Rio de Janeiro, Brazil. On the inselbergs of P ~ ao de Açucar and Morro S ~ ao Jo ~ ao, these plants grow on the south face of the cliff, where they form large , dense populations, along with sparse individuals of Tillandsia araujei Mez ( Bromeliaceae ) and two species of Cactaceae , Coleocephalocereus fluminensis (Miq.) Backeb. and Rhipsalis cereoides (Backeb. & Voll) Backeb.

Preliminary Conservation Status — Stigmatodon carioca was found in two subpopulations ca. 3 km apart, protected in conservation units (Morro da Urca and P ~ ao de Açucar Natural Monument and Chacrinha State Park), always on vertical rock wall habitat. Therefore, the suitable area for the species is very limited and fragmented. Sigmatodon carioca has a restricted distribution with an area of occupancy (AOO) estimated as 2.7 km 2. In addition, it is subject to a continuous decline in habitat quality, due to the proximity to the urban area, intense visitation by tourists, and the practice of rock climbing, with removal of mature individuals to open climbing routes in these locations. Given these characteristics and threats, we have preliminarily assessed S. carioca as Critically Endangered, based on the IUCN criteria [CR: B2ab (i, ii,iii)].

Etymology —In Brazilian Portuguese, the epithet carioca refers to people native to or inhabitants of Rio de Janeiro city, a region where S. carioca occurs, highlighting its type locality on the famous P ~ ao de Açucar massif.

Notes — Stigmatodon carioca is morphologically closely related to S. goniorachis , but is distinguished by its larger number of leaves in the rosette (up to 47 vs. up to 27); the dark-green leaf blade (vs. grayish green to vinous-green), which is not obscured by trichomes except for the parts with white crossbands (vs. partially obscured on both sides by a dense layer of cinereous trichomes); inflorescence up to 43.5 cm long (vs. up to 79 cm), the main axis with longer internodes (21–35 mm vs. 8.5–14(–27) mm long), which supports up to 23 flowers (vs. up to 29 flowers), flowers slightly longer, up to 46 mm (vs. up to 40.5 mm long), with sepal apex obtuse (vs. obtuse to rounded), wider petals (14–21 mm vs. 12.5–14 mm), white (vs. greenish-white), appendages longer (ca. 13 mm vs. 8–9.2 mm long), basally adnate to the petals for ca. 8 mm (vs. 2.3–3.2 mm), and the larger filaments measuring ca. 36 3 2 mm (vs. 15–18 3 1.4–1.6 mm), in addition to the traits cited in the diagnosis.

Stigmatodon carioca is also similar to S. costae but is distinguished by its smaller size when flowering (40–59 cm vs. 61–70 cm); leaf blades with revolute margins (vs. straight margins), dark green (vs. light green with a vinaceous longitudinal margin), densely white-lepidote, with trichomes forming white crossbands on both surfaces (vs. sub-densely lepidote adaxially with individuals glabrous abaxially, trichomes not forming white crossbands); inflorescence up to 43.5 cm long (vs. up to 38 cm), peduncle bracts elliptic (vs. obovate), main axis with longer internodes (21–35 mm vs. 15 mm long), sepals elliptic to ovate (vs. oblong-elliptic); petals white (vs. yellowish green), appendages longer (ca. 13 mm vs. 7.9 mm long), basally adnate to the petals for ca. 8 mm (vs. 5 mm); and longer style (26–28 mm vs. ca. 12 mm long).

The populations of P ~ ao de Açucar (PA) and Morro S ~ ao Jo ~ ao (MSJ) showed similar morphological characteristics with completely green leaves, with few trichomes distributed in the form of a transverse band and revolute leaf blade, simple inflorescence, green floral bracts with vinaceous apex, and white flowers. These two populations occur on the south face of the inselbergs.

Figures

FIG. 8. Stigmatodon carioca. A, B. Individual. C. Rosette. D. Leaf blade. E. Floral bracts. F. Flower. (Photos: V. C. Manh~ aes).

FIG. 9. Stigmatodon carioca. A. Habit. B. Sheath. C. Peduncle and inflorescence. D. Bract peduncle. E. Floral bract. F. Sepal. G. Flower. H. Petal, appendages, and stamens. I. Stigma. (B. D.R. Couto 3074 and L.I.T. Cardoso; remaining images: D.R. Couto 2378 and R. Moura).