Naiadendron A.G. Lima, Paula-Souza & Scalon, PhytoKeys 205: 222. 2022.

Bruneau, Anne, de Queiroz, Luciano Paganucci, Ringelberg, Jens J., Borges, Leonardo M., Bortoluzzi, Roseli Lopes da Costa, Brown, Gillian K., Cardoso, Domingos B. O. S., Clark, Ruth P., Conceicao, Adilva de Souza, Cota, Matheus Martins Teixeira, Demeulenaere, Else, de Stefano, Rodrigo Duno, Ebinger, John E., Ferm, Julia, Fonseca-Cortes, Andres, Gagnon, Edeline, Grether, Rosaura, Guerra, Ethiene, Haston, Elspeth, Herendeen, Patrick S., Hernandez, Hector M., Hopkins, Helen C. F., Huamantupa-Chuquimaco, Isau, Hughes, Colin E., Ickert-Bond, Stefanie M., Iganci, Joao, Koenen, Erik J. M., Lewis, Gwilym P., de Lima, Haroldo Cavalcante, de Lima, Alexandre Gibau, Luckow, Melissa, Marazzi, Brigitte, Maslin, Bruce R., Morales, Matias, Morim, Marli Pires, Murphy, Daniel J., O'Donnell, Shawn A., Oliveira, Filipe Gomes, Oliveira, Ana Carla da Silva, Rando, Juliana Gastaldello, Ribeiro, Petala Gomes, Ribeiro, Carolina Lima, Santos, Felipe da Silva, Seigler, David S., da Silva, Guilherme Sousa, Simon, Marcelo F., Soares, Marcos Vinicius Batista & Terra, Vanessa, 2024, Advances in Legume Systematics 14. Classification of Caesalpinioideae. Part 2: Higher-level classification, PhytoKeys 240, pp. 1-552 : 1

Naiadendron A.G. Lima, Paula-Souza & Scalon, PhytoKeys 205: 222. 2022.

Figs 172 , 173 , 178

Type.

Naiadendron duckeanum (Occhioni) A.G. Lima, Paula-Souza & Scalon [≡ Stryphnodendron duckeanum Occhioni]

Description.

Trees; indumentum composed of simple and granular trichomes; brachyblasts absent; branches unarmed, strongly striate, young shoots and leaves ferruginous with reddish granular trichomes, not odoriferous. Stipules caducous. Leaves bipinnate, not odoriferous; extrafloral nectaries on the petiole, rachis and pinnae; pinnae 10-22 pairs, subopposite to opposite; leaflets 15-23 pairs, opposite. Inflorescence units cylindrical spikes grouped in fascicles of 3-5 in pseudoracemes. Flowers 5-merous, white to yellowish; calyx gamosepalous; corolla gamopetalous; stamens 10, anthers with an apical gland; pollen in (12) 16-grained polyads; ovary included. Fruit a legume, dehiscent along both margins, linear to narrow-oblong, laterally-compressed; valves chartaceous. Seeds obovate or elliptic, wingless, ochre, pleurogram present.

Chromosome number.

Unknown.

Included species and geographic distribution.

Monospecific ( N. duckeanum ), from the northern Brazilian states of Acre, Amazonas and Rondônia (Fig. 178 ).

Ecology.

Rainforests (terra firme, often disturbed), on clay or sandy soil.

Etymology.

From naiades, Greek mythology’s nymphs of freshwater, and dendron (Greek = tree) in reference to the name given to the Brazilian Amazon (Naiades) by Carl Friedrich Philipp von Martius, where the single species of the genus occurs.

Human uses.

Unknown.

Notes.

Analysis of the extrafloral nectaries and fruits of Stryphnodendron duckeanum , initially described based on flowering material only, showed the species did not fit the limits of Stryphnodendron and that it could belong to Piptadenia (Rupert Barneby unpublished note; Scalon et al. 2022). Phylogenetic evidence reinforced segregation of the species from Stryphnodendron and showed it to be more closely related to Parapiptadenia and Pityrocarpa , thus supporting recognition of a distinct monospecific Naiadendron ( Simon et al. 2016; Borges et al. 2022; Lima et al. 2022).

Naiadendron and Parapiptadenia are the only members of the Stryphnodendron clade with typical legume fruits, i.e., dehiscing along both margins. However, Naiadendron is readily set apart by the ferruginous indumentum covering both its young branches and leaves. Strongly striate branches and petiolar nectaries 8-12 mm long also differentiate Naiadendron from all other members of the clade.

Taxonomic references.

Lima et al. 2022; Scalon et al. 2022; Simon et al. 2016.

Figures

Figure 172. Flowering branches in the Stryphnodendron clade A Gwilymia coriacea (Benth.) A. G. Lima, Paula-Souza & Scalon (Simon 3482) B Microlobius foetidus (Jacq.) M. Sousa & G. Andrade C Stryphnodendron adstringens (Mart.) Coville D S. gracile Rizzini & Heringer E Marlimorimia bahiana (G. P. Lewis & M. P. Lima) L. P. Queiroz & L. M. Borges F Pityrocarpa moniliformis (Benth.) Luckow & R. W. Jobson G Parapiptadenia blanchetii (Benth.) Vaz & M. P. Lima H Naiadendron duckeanum (Occhioni) A. G. Lima, Paula-Souza & Scalon (Simon 1457). Photo credits A, H MF Simon B T Iwane C, D H Moreira E LP Queiroz F D Cardoso G PG Ribeiro.

Figure 173. Habit and fruits in the Stryphnodendron clade A Marlimorimia psilostachya (DC.) L. P. Queiroz & Marc. F. Simon showing the tree habit B Stryphnodendron platyspicum Rizzini & Heringer (Simon 2017) showing the geoxyle subshrub habit C Gwilymia coriacea (Benth.) A. G. Lima, Paula-Souza & Scalon (Simon 3730) D Microlobius foetidus (Jacq.) M. Sousa & G. Andrade E Stryphnodendron rotundifolium Mart. fruit, manually opened revealing internal septa and seeds F Marlimorimia contorta (DC.) L. P. Queiroz & P. G. Ribeiro G Naiadendron duckeanum (Occhioni) A. G. Lima, Paula-Souza & Scalon (Pereira-Silva 15692) H Parapiptadenia rigida (Benth.) Brenan showing a yellow inflorescence and dehiscing fruit I Pityrocarpa leptostachya (Benth.) L. P. Queiroz & P. G. Ribeiro. Photo credits A R Aguilar B, C, E MF Simon D H Hulsberg F G Carvalho-Sobrinho G G Pereira-Silva H RT Queiroz https: // rubens-plantasdobrasil. blogspot. com / I LM Borges.

Figure 178. Distribution of Naiadendron based on quality-controlled digitised herbarium records. See Suppl. material 1 for the source of occurrence data.