Ceratonia L., Sp. Pl. 2: 1026. 1753.

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

Ceratonia L., Sp. Pl. 2: 1026. 1753.

Figs 7 , 11

Siliqua Duhamel, Traité Arbr. Arbust. 2: 261. 1755, nom. superfl.

Ceratia Adans., Fam. Pl. 2: 319. 1763. Type not designated.

Type.

Ceratonia siliqua L.

Description.

Long-lived, evergreen, small to medium-sized trees (to ca. 12 m) (Fig. 7F ) and shrubs, polygamous or dioecious or occasionally hermaphrodite; brachyblasts absent. Stipules minute, caducous or lacking. Leaves usually once pinnate, although bipinnate leaves rarely occur in C. siliqua ; leaflets opposite to alternate. Inflorescences short spike-like racemes, solitary or fasciculate, ramiflorous on main branches (Fig. 7J ) or clustered on young growth. Flowers commonly unisexual, apetalous, staminate flowers haplostemonous and bearing a pistilloide (Fig. 7I ), pistillate flowers sometimes bearing staminodes (Fig. 7H ), functionally bisexual flowers rare, calyx lobes (4) 5, imbricate, shortly connate at base, a very short hypanthium and a large pulviniform (cushion-like) disk present (Fig. 7H, I ); pollen tetracolporate ( C. siliqua ) or tricolporate ( C. oreothauma Hillc., G.P. Lewis & Verdc.); ovary short-stipitate. Fruits oblong, thick, indehiscent, dark brown and sub-woody when mature, with a sweet pulpy mesocarp ( C. siliqua , Fig. 7G ), or coriaceous to sub-woody, laterally compressed but with the valves raised over the seed chambers, mesocarp dry ( C. oreothauma ), many-seeded. Seeds very hard, ovate to oblong or pyriform, laterally compressed, separated by a pulpy, sugary mesocarp ( C. siliqua ), pleurogram lacking.

Chromosome number.

2 n = 24 ( Goldblatt 1981b).

Included species and geographic distribution.

Two species, one ( C. siliqua ) native to north-eastern Africa and the eastern Mediterranean (its native range uncertain due to its long history of cultivation), and Ceratonia oreothauma , with two distinct subspecies, one in Oman and Yemen and the other in the Somali Republic (Fig. 11 ).

Ecology.

Mediterranean scrubland (dry hillsides in garigue and coastal and submaritime maquis) ( C. siliqua ); rocky limestone slopes and gullies ( C. oreothauma ); 0-2000 m.

Etymology.

From ' Ceratonia ', ‘ceronia’ or ‘ceratea’ (Greek names for C. siliqua ), or possibly from ceras (Greek = horn) referring to the long, curved pods of C. siliqua .

Human uses.

Ceratonia siliqua is widely cultivated in the Mediterranean for forest-forage and its nutritious fruits; the Romans were harvesting the species as early as 79 AD. Carob seeds are said to be the original carat used as a standard weight by jewellers. Ceratonia siliqua is also used for wood, as a chocolate and coffee substitute, and occasionally to make alcohol. Carob seed gum is used in foods, cosmetics, medicines, photographic film emulsions, adhesives, paints, inks, and polishes ( Lewis 2005b). Ceratonia oreothauma subsp. oreothauma is used locally in Oman as goat fodder ( Hillcoat et al. 1980).

Notes.

The two Ceratonia species are differentiated, amongst other characters, by the pollen type, tetracolporate in C. siliqua and tricolporate in C. oreothauma ( Ferguson 1980; Graham and Barker 1981). Ceratonia siliqua is highly plastic in the sexuality of individual trees, in inflorescence branching pattern (racemose or cymose), in presence or absence of floral bracts, in organ number per whorl, missing floral organs, pollen grain form, and carpel cleft orientation ( Tucker 1992).

Taxonomic references.

Hillcoat et al. (1980); Lewis (2005b); Meikle (1977); Thulin (1993).

Figures

Figure 7. Flower, fruit, and vegetative characters of tribe Ceratonieae A Arcoa gonavensis Urb., foliage and fruits, Dominican Republic B Tetrapterocarpon geayi Humbert, fruits and part of bipinnate leaf, Madagascar (Du Puy M 410) C-E Acrocarpus fraxinifolius Wight & Arn., India, cultivated tree C inflorescence D dehisced fruits and new flush foliage E part of a bipinnate leaf F-J Ceratonia siliqua L. F tree, Jordan, semi-desert near Petra G fruits, Israel, Mt. Scopus Botanical Gardens, Jerusalem H pistillate flowers, Crete I staminate flowers, Crete J staminate inflorescences, Israel, Jerusalem Botanical Gardens. Photo credits A F Jimenez R. B D Du Puy C-E https: // efloraofindia. com / 2011 / 02 / 01 / acrocarpus-fraxinifolius / E D Valke F, G, J O Fragman-Sapir H, I G Lewis.

Figure 11. Distribution of Ceratonia based on quality-controlled digitised herbarium records. Note that many distribution points observed here are from cultivated Ceratonia specimens. The true native range of the genus Ceratonia is likely to be more restricted than depicted on the map. See Suppl. material 1 for the source of occurrence data.