Entada polystachya var. polyphylla (Bentham, 1840) Barneby, 1996

Caraballo-Ortiz, Marcos A., 2013, Rediscovery of Arrabidaea chica (Bignoniaceae) and Entada polystachya var. polyphylla (Fabaceae) in Puerto Rico, Phytotaxa 125 (1), pp. 53-58 : 54-55

Entada polystachya var. polyphylla

Entada polystachya var. polyphylla is a liana that can grow to 10 m long with flowers arranged in a terminal raceme of cylindrical spikes bearing white stamens, and produces flat pods that separate into one-seeded segments ( Acevedo-Rodríguez 2005). This taxon is present in South America (Amazonian Brazil, Ecuador, Peru, southwest Venezuela and the Guianas) and Puerto Rico ( Barneby 1996). In Puerto Rico, E. polystachya var. polyphylla is known from two collections made by Sintenis and Stahl (Urban 1903–1911). Sintenis collected a flowering individual on 5 February 1885 at the base of a hill named “Monte de Mula” next to a river in the municipality of Fajardo in northeastern Puerto Rico (Sintenis 1240, B!, BM!, GH!, L!, LD!, S!, US!, W!) ( Fig. 1 ). On October of the next year, Stahl collected a flowering individual in a sandy area between the municipalities of Manatí and Vega Baja in northern Puerto Rico (Stahl 590, B!; Fig. 1 ). As no more specimens of E. polystachya var. polyphylla were collected again, it was considered extremely rare or extirpated ( Acevedo-Rodríguez 2005, Axelrod 2011).

In July 2009, a solitary individual of E. polystachya var. polyphylla was found near Road PR- 191 in the municipality of Naguabo in the eastern region of Puerto Rico (Caraballo 2921, UPR!) (18°15' N 65°47' W; 345 m a.s.l.; Fig. 1 ). This locality is about 16 km southwest from the town of Fajardo, and although the exact position of the historical collection made by Sintenis is uncertain, both the historical and the current locality are in eastern Puerto Rico ( Fig. 1 ). The individual of E. polystachya var. polyphylla was about 9 m long, flowering, and growing over other trees in a sunny area with large rocks. The surrounding vegetation was disturbed and included grasses, invasive vines, and some persisting cultivated plants. Other uncommon native vines found at the site were Dioclea reflexa Hook. f. (Fabaceae-Faboideae) and Mucuna urens (L.) DC. (Fabaceae-Faboideae).

Like A. chica , E. polystachya var. polyphylla is listed as a critical element of the flora of Puerto Rico by the Department of Natural and Environmental Resources of The Commonwealth of Puerto Rico ( DNER 2008). Nevertheless, the only known individual of the species in Puerto Rico is on a private property and threatened by deforestation and wild fires. In addition, it should be noted that, although the flowers observed seems healthy, after flowering the inflorescence spikes became swollen and no fruits were observed (Caraballo 2921, UPR!). Further research is necessary to determine the cause of this deformity and the fertility of the individual. The successful conservation of E. polystachya var. polyphylla in Puerto Rico depends on the protection and propagation of the mentioned plant.

Figures

FIGURE 1. Map of the island of Puerto Rico showing the localities where the lianas Arrabidaea chica (circle) and Entada polystachya var. polyphylla (triangle) were rediscovered. The historical localities where E. polystachya var. polyphylla was collected during the 19th Century includes the municipality of Fajardo (rhombus) and the area between the municipalities of Manatí and Vega Baja (square). All the historical records of A. chica are from unspecified localities within the municipality of Bayamón.