Anthurium sect. Pachyneurium

Camelo, Mel C., Temponi, Lívia G., Coelho, Marcus A. N. & Baumgratz, José F. A., 2023, Taxonomic updates in Anthurium sect. Pachyneurium (Araceae) from the Brazilian Atlantic Forest, Phytotaxa 599 (2), pp. 109-125 : 114-123

Anthurium sect. Pachyneurium

from the Brazilian Atlantic Forest Domain: distribution and vegetation types

Most Brazilian species of Pachyneurium section occurs in the Amazon Domain, which is thus the main center of diversity ( Croat 1991). In the Atlantic Forest Domain, there are seven species reported ( Fig. 2 )— A. affine Schott (1855: 82) , A. leonii , A. paraguayense Engler (1898: 361) , A. plowmanii Croat (1987: 811) , A. pluricarinatum , A. santaritense Nadruz & Croat (2005: 28) and A. solitarium Schott (1860: 478) that can be identified by sets of distinctive morphological characteristics of the leaves, inflorescences, pollen grains, fruits, and seeds, as presented in the key and Figs. 3–8 .

Most of the species mentioned above are endemic of Brazil, except for A. paraguayense and A. plowmanii due it occurs in Bolivia, Paraguay, and Argentina ( Croat 1991). Indeed, most of the species here studied of A. sect. Pachyneurium are also endemic to the Atlantic Forest, except three: Anthurium affine (that occurs in Atlantic Forest, and can be found in Caatinga and Cerrado Domains; Coelho et al. 2020), A. paraguayense (that occurs in transition of Atlantic Forest/ Cerrado and Pantanal Domains; Croat 1991), and A. plowmanii (that occurs in Atlantic Forest/ Cerrado, Pantanal and Amazon Domains; Croat 1991).

Species distribution of Anthurium sect. Pachyneurium from Brazil is shown in Fig. 2 and Table 1 . Anthurium pluricarinatum increases to three the number of species found in the Brazilian Northeast Region, since previously only A. affine and A. solitarium were known from there. Furthermore, the species found can be distinguished by foliar and reproductive characteristics ( Table 2 ).

Even though the Brazilian Atlantic Forest Forest Domain is threatened, new species such as A. pluricarinatum continue to be described, warranting urgent efforts for the conservation of this phytogeographic domain. These actions must be associated with initiatives to describe the biodiversity and the ecological interactions between species in the Restinga environment.

Figures

FIGURE 2. Distribution map of Anthurium sect. Pachyneurium from the Brazilian Atlantic Forest Domain, including a new species Anthurium pluricarinatum. Data Source: IBGE (2017). Note: The colors represent the different types of vegetation and the abbreviation on the map (i.e., CE, RN, PB, PE, etc.) are the states of Brazil.

FIGURE 3. Anthurium leonii. A. Habit and pendent inflorescence. B. Leaf blade and inflorescence. C. Inflorescence pendent and spadix. D. Detail of the leaf blade, insculpated primary lateral veins and infructescence. E. Infructescence pendent with berries and marcescent spathe. F. Detail of bicolor berries. G. Details of seeds. H. Detail of fruit surface showing the tepal filaments from which the berries are suspended. I. Two seeds from dried material, and a berry with four tepal filaments embedded in mucilage. (Photos A-F. Raul Ribeiro).

FIGURE 4. Anthurium affine. A. Habit. B. Entire plant. C. Petiole adaxially sulcate with acute margins. D, E. Discolor leaf blade (adaxial and abaxial surfaces, respectively) with sharply wavy margins F. Details of midrib with 1 rib, and primary lateral veins prominent at adaxial surface G. Details of spathe H. Inflorescence erect with revolute spathe I. Cylindric spadix with yellow pollen grains J. Inflorescence at post-anthesis with immature berries K. Infructescence erect with bicolor berries L. Detail of seed.

FIGURE 5. Anthurium paraguayense. A. Specimen (G. Martinelii et al. 16817 (RB!) B. Habit and detail of inflorescence (arrow) shorter than half of the leaf. C. Inflorescence erect at post-anthesis and reflexed spathe. D. Infructescence erect with berries. E. Detail of concolor berries and seeds. (Photos D, E. Mauricio Caixeta).

FIGURE 6. Anthurium plowmanii. A. Habit B. Cataphylls in fibers fine, hairlike (arrow). C. Petiole U-shaped and peduncle shorter than petiole. D. Spadix longer than peduncle, tapered. E. Spadix in pre-anthesis. F. Detail of with nectar droplets. G. Inflorescence at anthesis erect and brownish. H. Detail of spadix in anthesis with pollen grains. I. Inflorescence erect in post-anthesis. J. Inflorescence in postanthesis showing one berry. K. Infructescence with red berries. L. Detail of berry: oblong, red, and gloss.

FIGURE 7. Anthurium santaritense. A. Habit. B. Petiole adaxially sulcate with obtuse margins and abaxially obtuse. C. Leaf blade D. Details of midrib prominent and primary lateral veins insculped at adaxial surface. E. Detail of inflorescence at pre-anthesis with revolute spathe. F. Inflorescence pendent and straight spathe at anthesis. G. Spadix stipitate and spathe forming an acute angle with peduncle. H. Spadix in pre-anthesis with nectar droplets. I. Spadix in anthesis with yellow pollen grains. J. Inflorescence and infructescence pendent. K. Infructescence with one berry L. Detail of concolor berries and seed. (Photos F–L. Lúcio Leoni).

FIGURE 8. Anthurium solitarium. A. Habit. B. Detail of petiole. C. Obovate to elliptic leaf blade. D. Midrib sulcate at the adaxial surface and leaf blade with slightly wavy margins. E. Details of midrib prominent at the abaxial surface and eucamptodromous vernation. F. Inflorescence pendent. G. Detail of white pollen grains. H. Spathe long-decurrent and forming an acute angle with peduncle. I. Spadix at post-anthesis. J. Infructescence pendent. K. Detail of concolor berries.