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Schwenckia americana L. Annual herb, in wooded savannah and open forest; also in cropland, fallow and disturbed sites. C.N.: kasuanza, suanza (kb). Uses: medicinal., Published as part of Monteiro, Francisca, Costa, Esperança Da, Kissanga, Raquel, Costa, José Carlos & Catarino, Luís, 2022, An annotated checklist of the vascular flora of Quiçama National Park, Angola, pp. 1-67 in Phytotaxa 557 (1) on page 49, DOI: 10.11646/phytotaxa.557.1.1, http://zenodo.org/record/6985699

Schwenckia aurantiaca Paucar & Stehmann, spec. nov. Figures 1–4. Type: — BRAZIL. Minas Gerais: Município de Jaíba, Reserva Biológica Serra Azul, Furados, 15°12’32”S, 43°51’16”W, 480 m, 15 April 2019, fl., fr., J.O.A. Paucar & J.R. Stehmann 203 (holotype BHCB195125!, isotype RB!). Diagnosis: — Schwenckia aurantiaca is characterized by the short cylindrical corolla with five linear orange appendages and triangular inter-appendicular lobes, and by the presence of two fertile stamens and three shorter staminodes. It is morphologically similar to S. glabrata Kunth in Humbold et al. (1817: 374), which differs in having a corolla with only two developed appendages, obcordate inter-appendicular lobes, and staminodes subequal to the fertile stamens. Annual herb, erect or ascending, up to 55 cm tall. Stem hollow, initially single, later with secondary branches arising from the basal nodes, green to olive-green, striated, puberulent at the base, distally glabrescent, pubescent with both eglandular and glandular trichomes, the eglandular trichomes antrorse, with 1–4 cells, the capitate-glandular trichomes with 1–3 cells. Leaves simple, alternate, those of the lower stem with blades 8–19.9 × 4–12 mm, elliptic, membranaceous, glabrous to glabrescent on both sides, abaxially sparsely pubescent along the midrib with antrorse eglandular trichomes, the base rounded, the apex mucronate, the venation brochidodromous, with up to 3 pairs of primary veins, the petioles 3–8.8 mm long, glabrescent, with eglandular trichomes; leaves of upper stems usually longer and narrowed, with blades 14.6–34.8 × 2–10.5 mm, lanceolate to oblong-lanceolate, sparsely puberulent on both faces with 1–4 celled, eglandular trichomes and minute, two-celled, glandular trichomes, abaxially the midrib marked, the base attenuate, the apex acute, the margin entire or slightly wavy, sparsely ciliate with 4-celled, eglandular trichomes, the venation brochidodromous, with up to 6 pairs of lateral veins, petioles 1–5.6 mm long. Inflorescences paniculate, with at least 3 flowers simultaneously opened in anthesis, distributed evenly along the branches, axis glabrous, the bracts 0.9–1.3 mm long, lanceolate, ciliate-pubescent with 1–3 celled, eglandular trichomes, the pedicels 0.6–1.6 mm long, glabrous. Calyx in anthesis tubular, the tube 1.9–3.1 mm long, the lobes 0.5–1.5 mm long, unequal, the apex acute, papillose, the abaxial and adaxial surfaces glabrescent with sparse 1–3 celled glandular trichomes. Corolla cylindrical, glabrous, the tube straight, 7.5–10.3 mm long, greenish-yellow, purple on the upper third, the five corolla lobes each with one central appendage and two lateral lobes, the appendages linear, 1–2.2 mm long, unequal, one visibly smaller, green in pre-anthesis, changing to orange at anthesis, the inter-appendicular lobes unequal, 0.3–0.7 mm long, triangular, reflexed, papillose at the margin. Androecium with 2 fertile stamens, the anthers 0.7–1.1 mm long, connivent, the filaments free, 3.2–5.2 mm long, adnate in the lower third of the corolla tube, pilose at the base with mostly 4-celled (a few 5-celled), eglandular trichomes, the staminodes 3, 0.6–1.6 mm long, unequal, lanceolate to subulate, pilose with trichomes like those of the fertile stamens. Nectariferous disk present. Ovary 2-locular, 0.7–1.1 × 0.4–0.6 mm, subglobose, the style 5.9–7.5 mm long, the stigma capitate. Calyx persistent in fruit, tearing to the base. Fruiting pedicel up to 3 mm long. Capsule 2.6–3.8 × 2.1–3.6 mm, subglobose. Seeds 5–14, 0.7–1.4 × 0.6–0.8 mm, cuboidal to polyhedric, testa reticulate-foveolate. Chromosome number: unknown. Distribution, habitat, and ecology:— Schwenckia aurantiaca has a restricted distribution, known only from an unusual ecosystem regionally called Furados, at Serra Azul Biological Reserve in the northern Minas Gerais (Fig. 4). The typical vegetation is the arboreal Caatinga where Cavanillesia umbellata Ruiz & Pavón (1798: 166) (Malvaceae) is commonly found, with islands of calcareous outcrops, open areas with exposed rocks, and depressions that are seasonally flooded during the rainy season (Fig. 4B–C). This seasonally dry vegetation is adapted to the semi-arid climate of the region, classified as Aw-tropical with dry winter (Reboita et al. 2015). The temporarily flooded, open areas are the habitat of the new species, which is an annual plant. The seeds germinate in the rainy season, which is when the plant grows, reproduces, and dies, leaving seeds in the soil to germinate in the next rainy season. Anthesis observed in cultivation, is nocturnal and has a cycle that begins with the opening of the corolla lobes in the late afternoon or early evening and closing at dawn the next day, a process repeated for three consecutive days. The tubular corolla, the nocturnal anthesis, and the sweet fragrance released at night suggest that moths may be the pollinators of S. aurantiaca. Etymology: —The specific epithet “ aurantiaca ” comes from Latin and means orange, an allusion to the color of the corolla appendages during anthesis. Phenology: —Flowering and fruiting occur from February to April. Conservation status: —Critically Endangered (CR) [B1, B2b(i,iii), D]. Schwenckia aurantiaca is known only from one area of Serra Azul Biological Reserve, with one or few populations (S. aurantiaca is Critically Endangered (IUCN 2020). Paratypes: — BRAZIL. Minas Gerais: Municipality of Jaíba, Reserva Biológica Serra Azul, Furados, 15°12’26”S, 43°51’17”W, 480 m, 20 February 2017, fl., fr., J. R. Stehmann et al. 6406 (BHCB186348); Reserva Biológica Serra Azul, Furados, 15°12’26”S, 43°51’17”W, 480 m, 20 February 2017, fl., fr., J. R. Stehmann et al. 6444 (BHCB190182)., Published as part of Paucar, Jenny Olga Arrea & Stehmann, João Renato, 2021, Schwenckia aurantiaca (Solanaceae), a new species from calcareous outcrops of northern Minas Gerais, Brazil, pp. 166-174 in Phytotaxa 508 (2) on pages 167-172, DOI: 10.11646/phytotaxa.508.2.5, http://zenodo.org/record/5425896, {"references":["Ruiz, H. & Pavon, J. (1798) Systema vegetabilium florae peruvianae et chilensis, characteres prodromi genericos differentiales, specium omnium differentias, durantionem, loca natalia, tempus florendi, nomina vernacula, vires et usus nonullis illustrationibus interspersis complectens. I - VI. Gabriel de Sancha, Madrid, 456 pp. https: // doi. org / 10.5962 / bhl. title. 887","Reboita, M. S., Rodrigues, M., Silva, L. F. & Alves, M. A. (2015) Aspectos climaticos do estado de Minas Gerais. Revista Brasileira de Climatologia 17: 206 - 226. https: // doi. org / 10.5380 / abclima. v 17 i 0.41493","Barbosa, R. S. & Santos, F. D. (2008) Unidades De Conservacao, Conflitos Socioambientais e o encurralamento das Populacoes locais no Norte de Minas. In 46 th Congress, Rio Branco, Acre, Brasil. Sociedade Brasileira de Economia, Administracao e Sociologia Rural (SOBER). https: // doi. org / 10.22004 / ag. econ. 109655","IUCN Standards and Petitions Committee (2020) Guidelines for Using the IUCN Red List Categories and Criteria. Version 14. Prepared by the Standards and Pettions Committee. Available from: http: // cmsdocs. s 3. amazonaws. com / (accessed 2 March 2020)"]}

The tribe Schwenckieae (Solanaceae) is characterised by the presence of appendages on the corolla, a diagnostic trait for the group. These appendages constitute a median distal projection of the three-lobed petal and occur in the genera Melananthus and Schwenckia but are absent in Heteranthia. We investigated the micromorphology and anatomical structure of the appendages and lateral petal lobes of Schwenckia americana (two varieties), S. angustifolia, S. curviflora and S. novaveneciana, and Melananthus fasciculatus. We also performed histochemical tests to determine if the appendages are involved in the production of volatiles, acting as a fragrance secretory structure (osmophore). The appendages have a uniseriate epidermis, whose cells store phenolics and lipids. The parenchyma is starch-rich just prior to anthesis in all species studied. The sensory test and anatomical analyses identified scent-secreting tissues, not only in the appendages, but also in the lateral petal lobes, whose cells are papillose with a sculptured surface. The α-naphthol p-phenylenediamine (NADI) reaction detected volatile (essential oils) compounds in S. americana var. americana and S. americana var. angustifolia. We demonstrated the secretory tissues and the production of lipids in the corolla appendages of Schwenckia and Melananthus, which indicate their osmogenic function and probable scent emission to attract pollinators.

CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Schwenckieae (Solanaceae) é uma pequena tribo com distribuição neotropical, representada por três gêneros, Schwenckia, Melananthus e Heteranthia, e cerca de 31 espécies. É a única tribo da família caracterizada morfologicamente pela presença de apêndices na corola. As flores da maioria das espécies da tribo apresentam tipicamente pétalas com limbo emarginado, com dois lóbulos laterais e um lóbulo mediano aqui denominado apêndice, que varia em tamanho e forma. A presença dos apêndices da corola é considerada uma característica taxonômica importante, mas sua função é ainda desconhecida. As características da flor, como a forma da corola tubulosa, a abertura da flor durante a noite e a presença do odor sugerem a polinização realizada por mariposas e que os apêndices estejam envolvidos no processo, atuando como estruturas secretoras de perfume (osmóforos), hipótese aqui testada. Para esse estudo investigamos a micromorfología e a anatomia de quatro espécies de Schwenckia, S. americana (e duas variedades), S. angustifolia, S. curviflora e S. novaveneciana, e uma espécie de Melananthus, M. fasciculatus. Os apêndices apresentam características secretoras, com epiderme glandular unisseriada, rugosa, ausência de estômatos, feixe vascular anficrival, com porção floemática mais desenvolvida do que a porção xilemática, e tecido parenquimático com grãos de amido, que são consumidos no início da antese. O teste sensorial indicou odor forte e adocicado. A análise anatômica evidenciou ser este odor oriundo não só dos apêndices, mas também dos lóbulos laterais da corola que têm superfície glandular papilosa. S. americana var. americana foi o único táxon que não apresentou odor pelo teste sensorial, mas manteve atividade metabólica nos apêndices, evidenciada pelo vermelho neutro. A presença de óleos essenciais (compostos voláteis) e fenólicos, descritos como sendo relacionados à composição do buquê floral, além do acúmulo de reservas lipídicas no estádio de pré-antese e seu consumo em pós-antese, indicam que os apêndices desenvolvidos dos gêneros Schwenckia e Melananthus são osmóforos com identidade morfológica definida. Esses resultados confirmam ter, os apêndices presentes na tribo Schwenckieae, uma função osmogênica e voltados à atração dos polinizadores. Schwenckieae (Solanaceae) is a small tribe with neotropical distribution, represented by three genera, Schwenckia, Melananthus and Heteranthia, group containing approximately 31 species. It is the only tribe of Solanaceae characterized morphologically by appendices in the corolla. The flowers of most species of this tribe typically have petals with emarginated limbo, with two lateral lobules and a central lobule here called appendix, which varies in size and shape. The presence of the appendices of the corolla is considered an important taxonomic characteristic, but its function is still unknown. The floral feature, such as tube-shaped corolla, flower opening at night and odor, suggest the pollination performed by moths and that the appendices are involved in the process, acting as perfume-secreting structures (osmophores), hypothesis tested here. Currently, we investigated the micromorphology and anatomy of four species of Schwenckia, S. americana (and two varieties), S. angustifolia, S. curviflora and S. novaveneciana, and one species of Melananthus, M. fasciculatus. The appendices have secretory characteristics, with uniseriate rough glandular epidermis, absence of stomata, anficrival vascular bundle, with more developed phloematic than xylematic portion, and parenchymatic tissue with starch grains, which are consumed in the anthesis stage. The sensorial test indicated a strong and sweet odor. The anatomical analysis evidenced that this odor originated not only from the appendices, but also from the corolla lateral lobules that have papillary glandular surface. S. americana var. americana is the only taxa without odor, which nevertheless maintained the metabolic activity in the appendices, evidenced by neutral red. The presence of volatile compounds, such as essential oils and phenolic compounds, are being reported as part of floral bouquet, and the accumulation of lipid reserves in the pre-anthesis stage and their consumption in post-anthesis indicate that the appendices are osmophores with defined morphological identity. These results confirm that the appendices present in the Schwenckieae tribe have an osmogenic function and must be involved in the mechanism of attracting pollinators.

Se describe e ilustra una nueva especie del genero Schwenckia (Solanaceae) encontrada en el Departamento del Caqueta, Cordillera Oriental de Colombia, Schwenckia alvaroana Benitez. La misma se distingue del resto de las especies de la seccion Schwenckia por su habito trepador y sus corolas de menor tamano. Tambien se proporciona una clave para separar las especies hasta ahora reconocidas de la seccion Schwenckia.

Schwenckia americana Linnaeus, Genera Plantarum, ed. 6: 577. 1764. "Habitat in Barbyce." RCN: 137. Lectotype (Knapp in Jarvis & al., Regnum Veg. 127: 86. 1993): Herb. Linn. No. 31.1 (LINN). Generitype of Schwenckia Linnaeus. Current name: Schwenckia americana L. (Solanaceae)., Published as part of Jarvis, Charlie, 2007, Chapter 7: Linnaean Plant Names and their Types (part S), pp. 806-877 in Order out of Chaos. Linnaean Plant Types and their Types, London :Linnaean Society of London in association with the Natural History Museum on pages 827-828, DOI: 10.5281/zenodo.291971