Updated synopsis of Acalypha (Euphorbiaceae, Acalyphoideae) from Brazil

A critical taxonomic and nomenclatural review of the Brazilian species of Acalypha (Euphorbiaceae, Acalyphoideae) is presented. As a result, 40 species (44 taxa including six subspecies) are accepted, 37 of them native (17 endemic) and three introduced; also, 132 names are considered synonyms, 28 of them for the first time. Two new combinations are proposed: Acalypha brasiliensis subsp. asterotricha and A. brasiliensis subsp. psilophylla, previously considered varieties of A. brasiliensis. Information about types is provided for all the valid names, and 54 lectotypes and one neotype are designated. Identification keys and detailed distribution maps of all the native taxa are also provided.


Introduction
Acalypha L. is one of the most species-rich genera of the family Euphorbiaceae. It includes ca. 500 species of mainly small trees and shrubs distributed in the tropics and subtropics, but some herbaceous species are also found in temperate regions. The Americas are home to around 250 species, which are distributed from southeastern Canada and the USA, to Uruguay and northern Argentina. The species are found in a wide variety of habitats, from tropical rainforests to subdesertic areas, and range from sea level to 4000 m of altitude (Cardiel and Muñoz-Rodríguez 2012). More detailed information on the presence of Acalypha in the New World can be found in Cardiel et al. (2013b).
The present work is part of the ongoing revision of Acalypha for South American countries and has been preceded by the taxonomic revisions or synopses for Colombia (Cardiel 1995a), Venezuela (Cardiel 1999), Ecuador (Cardiel and Muñoz-Rodríguez 2012), Peru and Bolivia (Cardiel et al. 2013b), and Argentina, Uruguay, and Paraguay (Cardiel and Muñoz-Rodríguez 2015).
Brazilian Acalypha were first treated nationally in the massive Martius' Flora Brasiliensis (Müller-Argoviensis 1874). In that work, 34 species and 39 varieties of Acalypha were accepted, 12 of which were described for the first time.
The aims of this work are to present an updated critical synopsis of the species of Acalypha from Brazil, including a complete nomenclatural review, and to provide a taxonomic key to facilitate their identification.
The structure of the synopsis generally follows that employed in previous works Muñoz-Rodríguez 2012, 2015). The accepted native species are cited in alphabetical order, followed by the accepted introduced or cultivated species, also in alphabetical order. Each species treatment includes original publications, homotypic synonyms, and nomenclatural synonyms. Only the synonyms based on Brazilian specimens are included, and some names previously cited as accepted for this country. We include the notation "syn. nov." whenever we newly treat a name as a synonym. Each new synonym is proposed after careful review of its original description and type specimen(s). For each name, information about the type collections is included. Any novel designation of types was made after a careful review of the original literature of the taxa and examination of original material. When no holotype was indicated, or it was lost or destroyed, a lectotype or neotype was designated, according to the rules of the International Code of Nomenclature (Turland et al. 2018), and the recommendation of McNeill (2014). When no holotype was indicated, but a single specimen housed in the institution where the author is known to have worked exists, or if a single specimen with a label clearly in the author's hand is available, we designate it as "lectotype or perhaps holotype" according to the recommendation by McNeill (2014). The remaining designations of lectotypes are justified in the "notes" section of each species.
All the referenced specimens have been examined, except those marked as "not found"; barcode numbers of type specimens are cited when available. References to illustrations (when available) and descriptions are also cited. Under the "distribution and habitat" section we list the general geographic distribution of each species in Americas, following Taxonomic Database Working Group standards (Brummitt 2001), and the detailed Brazilian distribution, indicating the geographic Brazilian regions, according to IBGE (2004), and the states of each region where the species have been found; then, we indicate the Brazilian biomes (according IBGE 2004), and altitudinal range. Finally, we indicate the total number of specimens reviewed for each taxon. All this information was obtained exclusively from the studied specimens. In the references section, we include mainly works citing species A. apetiolata, A. brasiliensis, A. digynostachya, A. gracilis, A. herzogiana, A. klotzschii, A. macularis, A. martiana, A. multicaulis, A. peckoltii, A. pohliana, A. radicans, and A. uleana. The Cerrado biome is the main home of A. chorisandra, A. clausenii, A. communis subsp. apicalis, and A. communis subsp. communis, A. dimorpha, A. variabilis, and A. velamea, although some of these species can also appear in disturbed Atlantic Forest; A. amblyodonta can also appear in the Cerrado biome. In the Amazonia biome, the most characteristic species are A. acuminata, A. cuneata, A. scandens, A. stachyura, and A. stricta. In the Caatinga biome there appear mainly A. inselbergensis and A. multicaulis, but the latter is also frequent in Cerrado and disturbed Atlantic Forest areas. In the Pampa biome, the most characteristic species are A. communis subsp. tracheliifolia, A. sehnemii, and A. senilis; A. velamea is also found there. Finally, only the poorly known A. ampigyne seems to be associated with the Pantanal Biome. Species with a wide distribution, not clearly associated with any of the aforementioned biomes, are A. arvensis and A. poiretii, species usually associated with anthropic areas, and A. diversifolia, A. macrostachya, and A. villosa, species widely distributed throughout the Neotropics.
It should be noted that several species are poorly known and represented by a small number of collections. Acalypha amphigyne, A. chorisandra, and A. pohliana are only known from the type specimen, in all cases collected over a century ago. Acalypha dimorpha, A. macularis, A. peckoltii, and A. radicans have only two or three collections from the last decades, in addition to the nineteenth-century type collections. It is very likely that some of these species are extinct or, at least, highly threatened.
Other more recently described species, such as Acalypha almadinensis, A. apetiolata, and A. sehemii, appear to be highly restricted endemics for which very few collections are known. Further field work is necessary to clarify the situation and conservation status of these species. The case of A. inselbergensis is remarkable. This species was described in 2018 based on a single collection, but immediately after that, once this new species was recognized as such, it was discovered to be widely distributed in the Caatinga biome, and more than 30 collections of this species are currently known (Maciel-Júnior et al. 2020).
Finally, we must point out that the diversity and complexity of Brazilian species of Acalypha is still not resolved satisfactorily. A more detailed study of some species is necessary, as well as having the support of the results of the phylogenetic works in progress. It is also necessary to increase efforts to search for species that are supported by a small number of collections. sepals, and with small, non-accrescent bracts. The styles are reddish, distinct or basally connate, divided several times into filiform segments, or rarely unbranched. The fruits are capsular, 3-lobed, usually papillose or muricate, and covered by different types of trichomes. The seeds are small, ovoid, and minutely foveolate. l e a f b l a d e s a c u t e a t a p e x ; i n f l o r e sc e n c e s a x i l l a r y o r t e r m i n a l … … … … … … …………………… 11 11a Some inf lorescences terminal; androgynous inflorescences sessile or shortly pedunculate (peduncle up to 0.5 mm long); mature pistillate bracts up to 12 mm long …………. 12b Leaf blades oblong to elliptic lanceol a t e , p u b e s c e n t ; t e r m i n a l i n f l o r e s c e n c e s a n d r o g y n o u s … … … … . . … … … … … … ………………………… A. dimorpha 13a Stipules filiform; androgynous inflorescences pedunculate; mature pistillate bracts deeply divided … ………………………………………………………… ……..….. A. amphigyne 1 3 b St i p u l e s t r i a n g u l a r-l a n c e o l a t e , b ro a de n e d a t t h e b a s e ; a n d r o g y n o u s i n f l o r e scences sessile; mature pistillate bracts den- 22a Pistillate inf lorescences densely f lowered, ellipsoid or cylindrical, with the axis completely covered by the bracts, not conspicuously visible ……………………………..…………. 23 22b Pistillate inflorescences loosely flowered, cylindrical, with the axis conspicuously visible between the bracts ………………………… 25 23a Pistillate bracts with triangular awnless teeth ………………………….. A. poiretii (in part) 2 3 b P i s t i l l a t e b r a c t s w i t h l o n g aw n e d teeth ……………………………………….…………. 26 24a Young branches and leaves with glandular trichomes; leaf blades acuminate at apex; pistillate inflorescences axillary and terminal; styles unbranched ………….. A. alopecuroidea 24b Young branches and leaves with only simple trichomes; leaf blades acute at apex; pist i l l a t e i n f l o r e s c e n c e s a x i l l a r y ; s t y l e s Iconography: Not found. Description: Pax and Hoffmann (1924: 118), Sousa et al. (2017: 340).

Key to the species of Acalypha of Brazil
Distribution and habitat: Endemic to Brazil: Southeast (Espirito Santo, Minas Gerais, Rio de Janeiro, and São Paulo). Atlantic Forest, 10-600 m a. s. l. 74 specimens studied (Fig. 1a).
Notes: Acalypha weddelliana was described based on three different Brazilian collections (syntypes), M.A. Weddell s.n., A. Saint-Hilaire Cat. A 1 nº 644, and A. Saint-Hilaire s.n. We selected the best preserved of those specimens, M.A. Weddell s.n. at P as the lectotype.

Acalypha estrellana was described based on two different Brazilian collections (syntypes), M.A. Weddell 677 and 794.
We selected the best preserved of those specimens, M.A. Weddell 677 at P, as the lectotype.
The type specimen of Acalypha teniuiramea was wrongly quoted as "in insula Orjan Oceani Pacifici" by Müller-Argoviensis (1866). The Wilkes Expedition to the Pacific Ocean (1838-1842) made a brief visit to Rio de Janeiro from November 1838 to January 1839 (Stanton 1975). The type specimen of A. teniuiramea was probably collected in the Serra dos Órgãos (Organ Mountains), in the vicinity of Rio de Janeiro, in addition to the type specimen of A. brevibracteata (= A. brasiliensis subsp. psilophylla).
Notes: Acalypha acuminata was described based on a single collection, R. Spruce 1643+, of which we have found eight duplicates. Due to the lack of a holotype indication, we designate the best preserved specimen at K, as the lectotype. Description: Pax and Hoffmann (1924: 120), Sousa et al. (2017: 340). Notes: Acalypha amblyodonta var. hispida was described based on a single collection, A.F. Regnell 1065, of which we have found six duplicates. Due to the lack of a holotype indication, we designate the best preserved specimen at S, as the lectotype.  References: Pax and Hoffmann (1924: 40).

Acalypha almadinensis
Notes: Acalypha amphigyne was described based on a single Brazilian collection, S. Moore 1024, of which we have found four duplicates. Due to the lack of a holotype indication, we designate the best preserved specimen at K, as the lectotype. Pax and Hoffmann (1924: 40) considered Acalypha amphigyne as a "anomalous form" of A. communis var. hirtiformis. The type specimens of Acalypha amphigyne present androgynous axillary inflorescences with a single pistillate bract at the base, clearly different from the inflorescences of A. communis, and no anomalous structure has been observed; therefore, we consider that this species should be accepted, although is only known from the type collection.
The type specimen of Acalypha amphigyne was collected over a century ago, so we cannot rule out the possibility that the species is now extinct. Iconography and description: Costa Allem and Watcher (1977: 87, fig. 3).
Notes: Acalypha apetiolata can be included in the recently defined Acalypha sect. Communes, a complex group of species widespread in north of the Southern Cone (Cardiel et al. 2013a Iconography : Dodson et al. (1985: 245, tab. 92d).
Notes: Acalypha arvensis is frequently misidentified as A. aristata Kunth, but A. aristata is a synonym of the previously published A. alopecuroidea Jacq., an introduced species in Brazil. Sul, and Santa Catarina). Mainly in Atlantic Forest, also occur in Caatinga and Cerrado, 0-1000 (-1400) a. s. l. 538 specimens studied (Fig. 2b-d).
Acalypha brasiliensis is a morphologically complex species that includes numerous infraspecific taxa. The shape and size of the leaves can vary greatly, as can the density of the indument; in young specimens or branches, the stellate or fasciculate trichomes cover almost the entire plant, especially the lower leaf surface, which appears whitish; however, on old specimens the stellate trichomes can be very scarce and even disappear. A. brasiliensis is also one of the most common and widely distributed species of the genus in Brazil. After a careful review of the original material and the large number of collections available, we consider that the morphological differences justify the recognition of three different taxa with subspecies rank. Additional analyses are still necessary to elucidate the complexity of this species, but such studies, including the incorporation of molecular analyses, are beyond the scope of this work.
Notes: The basionym Acalypha brasiliensis var. asterotricha was first described by Müller Argoviensis, who recognized two forms (f. cordata and f. obtusa). We consider that the differences between them do not justify the recognition of these taxa. In order to fix the application of the name of this variety, it is lectotypified using original material of Acalypha brasiliensis var. asterotricha f. obtusa.
Notes: A remarkable feature of Acalypha brasiliensis subsp. brasiliensis is the presence of styloids on the lower surface of the leaves (not found in the other subspecies). This type of epidermal crystals, recently studied, is very infrequent in Acalypha; among the Brazilian species of the genus, they are only found in this subspecies and in A. inselbergensis  Iconography : Lourteig and O'Donell (1942: 303, fig. 8; 1943, tab 87).
The type specimen of Acalypha brevibracteata was wrongly quoted as "in insula Orjan Oceani Pacifici" by Müller-Argoviensis (1866) Acalypha brasiliensis var. brevipes was described based on a single Brazilian collection, J.E.B. Warming 1565, of which we have found three duplicates. Due to the lack of a holotype indication, we designate the best preserved specimen at C, as the lectotype.
Acalypha brasiliensis var. glabrata was described based on a single Brazilian collection, L. Riedel 374, of which we have found four duplicates. Due to the lack of a holotype indication, we designate the best preserved specimen at G, as the lectotype.
Acalypha noronhae was described based on a single Brazilian collection, H.N. Ridley, T.G. Lea and G.A. Ramage 109, of which we have found five duplicates. Due to the lack of a holotype indication, we designate the best preserved specimen at K, as the lectotype.
Notes: Acalypha chorisandra was described based on a single Brazilian collection, A. Saint-Hilaire cat. B 1 nº 1069, of which we have found two duplicates at P. Due to the lack of holotype indication, we designate the best preserved specimen as the lectotype.
Notes: Odonteilema claussenii, the basionym of Acalypha claussenii, was described based on five different Brazilian collections (syntypes), of P. Claussen: 84, 774, 775, 1114 and s.n. We selected the best preserved of those specimens, P. Claussen s.n. at K, as the lectotype.
Notes: Acalypha communis is a polymorphic species divided into five subspecies widespread in northern part of the Southern Cone (Cardiel et al. 2013a); three of them are found in Brazil. Some specimens of A. communis may have mixed characters that make it difficult to assign them to subspecies; hybrids are likely to appear in areas where the subspecies coexist.
Notes: Acalypha juruana was described based on a single Brazilian collection, E. Ule 5875, of which we have found several duplicates, one of them from B and presumed destroyed. Due to the lack of a holotype indication, we designate the best preserved specimen, at HBG, as the lectotype. Description: Pax and Hoffmann (1924: 85), Sousa et al. (2017: 342).
Notes: Acalypha digynostachya was described based on a single collection, A. Saint-Hilaire cat. C 2 nº 1131, of which we have found three duplicates at P. Due to the lack of a holotype indication, we designate the best preserved specimen as the lectotype. Acalypha striolata was considered a synonym of A. gracilis by Berry et al. (2007). Cardiel and Muñoz-Rodríguez (2015) considered A. striolata a distinct species, common in southern Brazil, Argentina, and Paraguay. After more study, we consider this species to be conspecific with the previously described A. digynostachya. Müll.Arg. in Martius,Fl. Bras. 11 (2)
Notes: Acalypha dimorpha was described based on two different Brazilian collections (syntypes), J.E.B. Warming 1558 and 1566. We selected the best preserved of those specimens, J.E.B. Warming 1558 at G, as the lectotype.
Notes: Acalypha gracilis var. fruticulosa was first described by Müller Argoviensis, based on a Brazilian specimen collected by Friedrich Sello (or Sellow, as he changed his name in 1814 when he went to Brazil) from the imprecise location "Brasilia meridionali", and deposited in the Berlin herbarium. Sello's herbarium and types were mostly destroyed in the Berlin herbarium fire of 1944. We found several collections by Eugen Warming identified as this taxon in handwritten notes by Müller Argoviensis, and have designated one of them, from C, as the neotype. Acalypha divaricata was described based on two different Brazilian collections (syntypes), C. Gaudichaud-Beaupré 1685 and F. Sellow s.n. We selected the best preserved of those specimens, C. Gaudichaud-Beaupré 1685 at P, as the lectotype.
Acalypha gracilis var. pubescens was described based on a single Brazilian collection, A.F. Regnell 249 in part, of which we have found six duplicates. Due to the lack of a holotype indication, we designate the best preserved specimen at S, as the lectotype. Chodat, Bull. Herb. Boissier, sér. 2, 5: 606. 1905 Cerrado, 590 m a. s. l. 3 specimens studied (Fig. 4c).

Acalypha herzogiana
Notes: In addition to the wild specimens found of this species, we also found several specimens of a cultivar of Acalypha herzogiana, usually from gardens or urban areas. This cultivar is of uncertain origin and is characterized by the showy terminal pistillate inflorescences formed by numerous densely clustered, ebracteate, pistillate flowers. It was studied by Steinmann and Levin (2011), who hypothesized that it is the result of homeotic mutation resulting in the stamens being replaced by styles. We found this cultivar of A. herzogiana in Goiás, Parana, Rio de Janeiro, and Santa Catarina (14 specimens studied). Iconography: Not found.
Notes: The collection of Acalypha macularis cited by Pax and Hoffman (A. Glaziou 13190) includes different specimens and localities from Rio de Janeiro and Minas Gerais. The single specimen with Pax's handwritten label (B, neg. F 5350) is from Rio de Janeiro, and was presumably destroyed (we only known it by a negative at F). We designated as the lectotype the duplicate found at G. Description: Pax and Hoffmann (1924: 111).

Acalypha martiana
Distribution and habitat: Endemic to Brazil: Southeast (Minas Gerais and Río de Janeiro). Atlantic Forest, 100-600 m a. s. l. 16 specimens studied (Fig. 5c). Iconography : Lourteig and O'Donell (1942: 322, fig. 13;1943, tab.  Notes: Acalypha tenuicaulis was described based on a single Brazilian collection, A. Saint-Hilaire cat. C 2 n o . 2622, of which we have found two duplicates. Due to the lack of a holotype indication, we designate the best preserved specimen at P, as the lectotype. Acalypha multicaulis var. tomentella was described based on three different Brazilian collections (syntypes), J.E.B. Warming 1618, J.E.B. Warming s.n., and L. Riedel 830. We found specimens only of J.E.B. Warming 1618, and designate the best preserved of those, at C, as the lectotype.
Acalypha multicaulis var. tenuispica was described based on a single Brazilian collection, A. Glaziou 11542, of which we have found two duplicates. Due to the lack of a holotype indication, we designate the best preserved specimen, at C, as the lectotype.
Notes: Acalypha peckoltii was described based on a single Brazilian collection, T. Peckolt 206, of which we have found three duplicates, only one of them at BR with a handwritten label recognizably by Müller Argoviensis (the duplicate at G is probably a fragment of the same specimen). Due to the lack of a holotype indication, we designate this specimen at BR as the lectotype or perhaps holotype.
Notes: Acalypha stricta was described based on a single Peruvian collection, E. Poeppig s.n., of which we have found four specimens at F, P, and W. Due to the lack of holotype indication, we designate the single specimen with a label clearly in the author's hand, at W, as the lectotype or perhaps holotype.