Serianthes Benth., London J. Bot. 3: 225. 1844.

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

Serianthes Benth., London J. Bot. 3: 225. 1844.

Figs 226 , 227 , 228 , 231

Albizia sect. Serianthes (Benth.) F. Muell., Fragm. 8: 165. 1874. Type: Albizia grandiflora (Benth.) F. Muell. [≡ Serianthes dilmyi Fosberg]

Type.

Serianthes grandiflora Benth.

Description.

Unarmed shrubs, 6-10 m, and trees to 27 m. Stipules linear to filiform, observed only in the seedling stage. Leaves bipinnate, extrafloral nectary circular or elliptical usually on the lower half of the petiole, additional nectaries usually on the leaf rachis and on the pinnae between the leaflets insertion; pinnae (4) 6-22 pairs, opposite or subopposite; leaflets (6) 8-25 (30) pairs per pinna, alternate except for the distal pair, sessile, mostly asymmetrical with a diagonal midvein. Inflorescence an umbel, raceme, or panicle composed of pedunculate spikes, pedunculate racemes or 1-4-flowered capitula. Flowers uniform, bisexual, 5-merous; calyx gamosepalous, valvate, usually circumscissile at the base; corolla gamopetalous, valvate, tube untied with the staminal tube in the lower part; stamens numerous, united into a tube at the base; pollen in 16-celled polyads with a perforated tectum in each locule; ovaries 1, less frequently 2, sessile. Fruits indehiscent to very tardily dehiscent (rarely), woody with transverse seeds which are isolated in a chamber each. Seeds flattened with a hard, black testa and a U-shaped pleurogram, lack a wing.

Chromosome number.

2 n = 26 (only two counts of Serianthes kanehirae Fosberg are known) ( Goldblatt 1981a; Cannon et al. 2015)

Included species and geographic distribution.

ca. 18 species, five subspecies, and two varieties, widely distributed in the Indo-Pacific region (Fig. 231 ). Fifteen species are restricted to the Pacific Islands of which six are endemic to New Caledonia, three occur in Indonesia, and three occur in New Guinea and/or Papua New Guinea. The distribution of Serianthes tenuiflora Benth. is unknown. Most taxa are island endemics, except for Serianthes dilmyi , which is more broadly distributed in Malesia, Papuasia, and New Caledonia. Serianthes is the only genus within the Archidendron clade not found in Australia.

Ecology.

The more widespread Serianthes dilmyi Fosberg is adapted to supralittoral habitats. The other Serianthes taxa occur from coastal shrub, moist forest to lowland wet tropical rainforest on calcareous or volcanic soils, but in New Caledonia Serianthes is also found in maquis on ultramafic (serpentine) soils ( Fosberg 1960; Nielsen et al. 1984b).

Etymology.

Serianthes is derived from the Greek serikon (= silk) and anthos (= flower) because the flowers of the tree have a silky appearance ( Wagner et al. 1999).

Human uses.

The wood of Serianthes was used traditionally mostly for canoes, paddles, traditional boats, traditional and ceremonial houses, and for storyboards ( Kanis 1979; Nielsen et al. 1984b; Demeulenaere et al. 2021). Other documented traditional uses are for medicine ( Demeulenaere et al. 2021), dye ( Kanis 1979), food (seeds), and necklaces ( Nielsen et al. 1984b). Oral histories surrounding Serianthes teach the youth about respect and imbue spirituality ( Demeulenaere et al. 2021). Commercially, species of Serianthes are used for paper pulp, plywood, and timber ( Pari and Lestari 1993).

Notes.

Three main revisionary treatments ( Fosberg 1960; Kanis 1979; Nielsen et al. 1984b) have been published since Bentham first described Serianthes in 1844. Nielsen et al. (1984b) recognised two subgenera: Serianthes subg. Minahassae and Serianthes subg. Serianthes . However, a recent phylogenetic study ( Demeulenaere et al. 2022) of eight of the 18 species, identified two monophyletic groups whose taxon make-up does not support this subgeneric division. One lineage consists of taxa belonging to Serianthes subg. Serianthes sect. Serianthes and Serianthes subg. Minahassae taxa, while the second lineage consists of Serianthes subg. Serianthes sect. Calycina I.C. Nielsen taxa.

The distribution of certain Serianthes taxa across different islands (and a few mainland areas) results in vernacular names being expressed in either different languages or even the same language, but with a different name. For example, the Palauan name of Serianthes kanehirae var. kanehirae Fosberg is ukall or kumer, while the Yapese name of Serianthes kanehirae var. yapensis Fosberg is gumor. Serianthes nelsonii Merr. occurs on two islands of the Mariana Islands archipelago. The CHamoru name for the tree is håyun lågu on Guam and tronkon guåfi on Rota.

Taxonomic references.

Bentham (1844); Fosberg (1960); Kanis (1979); Nielsen et al. (1984b).

Figures

Figure 226. Habit and leaf morphology diversity in genera of the Archidendron clade A Archidendron clypearia (Jack) I. C. Nielsen B Heliodendron thozetianum (F. Muell.) Gill. K. Br. & Bayly C Falcataria falcata (L.) Greuter & R. Rankin D Heliodendron basalticum (F. Muell.) Gill. K. Br. & Bayly E Serianthes kanehirae Fosberg var. kanehirae F Serianthes kanehirae var. yapensis Fosberg G Pararchidendron pruinosum (Benth.) I. C. Nielsen H Paraserianthes lophantha subsp. montana (Jungh.) Benth. with tomentose stems and leaves I Wallaceodendron celebicum Koord. Photo credits A C Ng B R Cumming C J Teo D D Richter E, F JB Friday G G Brown H F and K Starr I Plantoholic Sheila.

Figure 227. Inflorescence and flower diversity of genera in the Archidendron clade A Archidendron vaillantii (F. Muell.) F. Muell. B Archidendropsis paivana (E. Fourn.) I. C. Nielsen C Falcataria falcata (L.) Greuter & R. Rankin D Heliodendron thozetianum (F. Muell.) Gill. K. Br. & Bayly E Serianthes sp. F Pararchidendron pruinosum (Benth.) I. C. Nielsen G Paraserianthes lophantha (Willd.) I. C. Nielsen H Wallaceodendron celebicum Koord. Photo credits A, F A Furhmann B B Henry C JB Friday D S Worboys E T Rodd G AndyBonsai H Plantaholic Sheila.

Figure 228. Fruit and seed diversity of genera in the Archidendron clade A fruit of Archidendron lucyi F. Muell. (Brown 169) B open pod of Archidendropsis streptocarpa (E. Fourn.) I. C. Nielsen showing winged seeds C opened pod of Falcataria falcata (L.) Greuter & R. Rankin D Heliodendron xanthoxylon (C. T. White & W. D. Francis) Gill. K. Br. & Bayly opened pod (Hyland 9229) E Heliodendron basalticum (F. Muell.) Gill. K. Br. & Bayly winged seeds (Canning & B. Rimes 6173) F-H Serianthes dilmyi Fosberg showing the indehiscent (to very tardily dehiscent) (rarely) woody pods with transverse seeds which are each isolated in a chamber I Pararchidendron pruinosum (Benth.) I. C. Nielsen fruit and seedling J Paraserianthes lophantha (Willd.) I. C. Nielsen immature pods (Brown 204 A) K Wallaceodendron celebicum Koord. pod. Photo credits A, I, J G Brown B B Henry C JB Friday D, E Queensland Herbarium F-H R CJ Lim K Plantaholic Sheila.

Figure 231. Distribution of Serianthes based on quality-controlled digitised herbarium records. See Suppl. material 1 for the source of occurrence data.