Parkia

Description

Unarmed trees to 50 m high. Leaves bipinnate, alternate or opposite, petiole and rachis usually with extrafloral nectaries, often shortly pubescent; Inflorescence compound, consisting of a stout twig to 0.5 m long, sparsely branched or unbranched, bearing 2-10 or more flexible peduncles, each to 50 or more cm long and 0.5 cm in diameter, pendent, ending in a swollen, elliptical or clavate axis bearing numerous flowers. Flowers (in the Malesian species) of 3 kinds; Stamens 10, all fertile, shortly exserted; Ovary shortly stipitate; . For the anatomy of the seed coat of P. timoriana (as P. javanica), see .
Seeds up to 38 per pod, in one row, ellipsoid;

Distribution

Asia-Tropical: Pantropical: present tropical America: present
Pantropical with c. 35 species in 3 sections. Most numerous and diverse in tropical America. Only section Parkia, to which all the Malesian species belong, is pantropical. — , .

Pollination

Parkia speciosa and P. timoriana are pollinated by fruit-bats (Megachiro- ptera: Pteropodidae) []. The remaining Malesian species are also expected to be chiropterophilous, though a variety of animals including insects, birds and perhaps nonflying mammals may visit the flowers. The capitula produce a foetid odour and a copious nocturnal supply of nectar. In all the Malesian species the capitulum is yellowish; the fertile flowers usually have cream-coloured filaments and yellow anthers when fresh, and turn dirty yellow the next day. The nectar-secreting region is often brownish yellow. Where there is a basal staminodial fringe, it is pale cream.

Dispersal

Birds and mammals have been reported feeding on the fruits: hornbills on P. speciosa [], elephants and deer on P. sumatrana []; various species of monkeys (], and squirrels [] on Parkia species. There have been no studies of dispersal, however.

Germination. Seeds of P. timoriana (as P. javanica) have a hard testa and will germinate over a period of weeks following planting, whereas those of P. speciosa, which have a soft testa, germinate within two weeks of planting or not at all []. Seeds of P. timoriana can be stored at room temperature for long periods and scarification by filing, acid treatment or soaking promotes germination [].

Uses

The wood of Parkia species is generally not durable and not highly valued [Burkill]. For uses as food and medicine, see under the species.

Phytochemo

The seeds of P. timoriana (as P. roxburghii) and P. speciosa contain the nonprotein sulphurous amino acids djenkolic acid, N-acetyl djenkolic acid, and glutamyl cystine []. Cyclic polysulphides occur in the beans of P. speciosa and contribute to their foul smell []. Lectins with haemoglutinating activity have been isolated from the seeds of P. speciosa and P. timoriana []. See further the general phyto- chemical treatment on p. 15-27.

Citation

Taub. - in E. & P., Nat. Pflanzenfam. 3. 1891: 123
Hopkins - in Fl. Neotrop. 1986
Elias - in Polhill & Raven (eds.), Adv. Leg. Syst. 1. 1981: 153
Benth. - in J. Bot. 1842: 328
Hutch. - in Gen. Fl. Pl. 1964: 280
Benth. & Hook.f. - in Gen. Pl. 1865: 588
Benth. - in Trans. Linn. Soc. 1875: 360

Synonymy

Parkia R.Br in Denham & Clapp., Narr. Travels Africa, Bot. App.: 289. 1826

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