Adenanthera L.

George R. Proctor (2012). Flora of the Cayman Isands (Second Edition). Royal Botanic Gardens, Kew

Morphology General Habit

Unarmed trees; leaves bipinnate, the pinnae subopposite, the leaflets alternate

Morphology Reproductive morphology Flowers

Flowers very small, in long slender racemes, perfect or polygamous; calyx bell-shaped, 5-toothed; petals 5, united below the middle or nearly free

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 10, free, the filaments about as long as the petals; anthers bearing a deciduous gland

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary sessile, with many ovules

Morphology Reproductive morphology Fruits

Pods flat, linear, 2-valved, the valves becoming twisted and curled after dehiscence; seeds roundish, thick and hard.

Distribution

A small genus of 3 or 4 species, native of Africa, Asia and Australia.

Legumes of the World. Edited by G. Lewis, B. Schrire, B. MacKinder & M. Lock. Royal Botanic Gardens, Kew. (2005)

Note

The tribe Mimoseae (sensu Bentham, 1875) is retained here simply as a matter of convenience. All recent phylogenetic analyses indicate that Ingeae and Acacieae are derived from within Mimoseae (Chappill & Maslin, 1995; Käss & Wink, 1996; Luckow et al., 2000; Bruneau et al., 2001; Luckow et al., 2003; Herendeen et al., 2003a), making it a paraphyletic group at best. The most recent studies indicate that it may not even be monophyletic with respect to the Caesalpinioideae (Luckow et al., 2000; Bruneau et al., 2001; Luckow et al., 2003).

Although the outline of a new tribal classification of the mimosoids is emerging, we await better-supported phylogenies (based on more extensive data) before formalising new stable and useful groups. Some parts of the classification proposed here are better supported than others. Notably, the basal branches in Fig. 24 are poorly supported in most analyses and the relationships among the groups are likely to change as we acquire more data. As presently indicated (Luckow et al., 2003), the type genus Mimosa falls within the derived Piptadenia group which is in turn sister, and basally branching, to elements of Acacia and Ingeae (Fig. 24). A more narrowly circumscribed Mimoseae sens. strict. will thus leave the bulk of Mimoseae sens. lat. (i.e., as treated here) in need of new tribal allocation. The most conspicuous difference between the classification presented here and that of Lewis & Elias (1981) is the inclusion of tribe Parkieae within Mimoseae. The former was circumscribed based on imbricate aestivation of the calyx, and was considered the basal tribe within the Mimosoideae (Elias, 1981a). Recent phylogenetic analyses (Chappill & Maslin, 1995; Luckow et al., 2000; Bruneau et al., 2001; Luckow et al., 2003; Herendeen et al., 2003a), indicate that the two genera in the Parkieae, Parkia and Pentaclethra, are not sister taxa (Fig. 24). Pentaclethra is nested within Mimoseae in Luckow et al. (2000), but is either sister to caesalpinioid taxa in Bruneau et al. (2001) and Herendeen et al. (2003a), or part of a basal polytomy with Mimoseae and caesalpinioid taxa (Luckow et al., 2003). Both Parkia and Pentaclethra are included in the tribe Mimoseae pending additional data and tribal recircumscription.

Recent work (Luckow et al., submitted a) also indicates that the monospecific tribe Mimozygantheae should be subsumed in the Mimoseae near Piptadeniopsis and Prosopidastrum, currently in the Prosopis group. Otherwise, the informal groups within the Mimoseae recognised by Lewis & Elias (1981) are relatively well-supported by current phylogenies and only a few departures have been made from their system. Where relationships are either poorly supported or unresolved, the classification of Lewis & Elias (1981) is retained. The Xylia group is dismantled and the Adenanthera group recircumscribed to include Calpocalyx and Xylia . Desmanthus has been removed from the Dichrostachys group, as has Neptunia, in agreement with recent molecular and morphological phylogenetic studies (Harris et al., 1994; Hughes, 1998; Luckow, 1995, 1997). A new group is erected to accommodate Piptadeniastrum which is well separated from Newtonia in the most recent phylogeny (Luckow et al., 2000; 2003), and another to accommodate Cylicodiscus, which is more closely related to the clade containing the Prosopis, Leucaena, Dichrostachys, and Piptadenia groups than it is to the Newtonia group. Neptunia is well supported as sister to Prosopidastrum in recent analyses (Luckow et al., 2003) and is included in the Prosopis group here. Relationships of genera in the Prosopis group are not resolved, but the group is retained here as there is no evidence that it is not monophyletic. Genera newly described since 1981 include Alantsilodendron, Calliandropsis, Kanaloa, and Lemurodendron. Alantsilodendron and Calliandropsis are placed in the Dichrostachys group, and Kanaloa in the Leucaena group based on phylogenetic analyses (Hughes, 1998; Luckow, 1997; Luckow et al., 2000). Lemurodendron is tentatively included in the Newtonia group as suggested by Villiers & Guinet (1989). As treated here the Mimoseae comprises 40 genera and from (859)– 869–(879) species.

Most closely allied to Amblygonocarpus and Tetrapleura in the Adenanthera group (Luckow et al., 2000; 2003)

Habit

Trees

Ecology

Tropical primary and secondary rain forest (including swamp forest to coastal thicket), and seasonally dry forest to open woodland and scrub

Distribution

Asia (Sri Lanka [1 sp.], Indo-China & S China [2 spp.], Malesia [6 endemic spp.], Papuasia to SW Pacific [1 sp.]), Australia (N Queensland, 1 sp.), Madagascar (1 sp.) and 1 sp. throughout tropical Asia to Melanesia and Australia, and widely introduced in Africa and the Neotropics

Timothy M. A. Utteridge and Laura V. S. Jennings (2022). Trees of New Guinea. Kew Publishing. Royal Botanic Gardens, Kew

Distribution

A genus of 12 species, from tropical Asia, Australia and the western Pacific. Two species in New Guinea: the endemic Adenanthera novoguineensis Baker f., and more widespread A. pavonina L. which is cultivated throughout Asia but appears to be native to New Guinea. Nielsen (1992) restricts A. microsperma Teijsm. & Binn. to western Malesia and the Lesser Sunda Islands.

Morphology General Habit

Trees and shrubs to 40 m tall, unarmed, sometimes buttressed (in New Guinea)

Morphology Leaves Stipules

Stipules inconspicuous, caducous

Morphology Leaves

Leaves bipinnate, glands absent, leaflets alternate, petiolulate

Morphology Reproductive morphology Inflorescences

Inflorescences in upper axils, solitary or paired, spiciform racemes, pendulous or erect

Morphology Reproductive morphology Flowers

Flowers bisexual, uniform, 5-merous, pedicels articulated, basal part persisting after flowering; stamens 10, free, anthers with an apical, stipitate gland on the connective

Morphology Reproductive morphology Fruits

Fruit chartaceous to coriaceous, narrow, straight, curved or twisted, dehiscent along both surfaces, endocarp separating slightly from epicarp

Morphology Reproductive morphology Seeds

Seeds red or red and black, ovoid, ellipsoid or orbicular, funicle thick, holding seeds obliquely in pod for a long time after dehiscence.

Ecology

Adenanthera is found in primary and secondary rain forests, open woodland, forest margins, strand and beach vegetation, from sea level to 600 m.

Recognition

Adenanthera can be recognised by the alternate leaflets, long racemose inflorescences, jointed pedicels, the base of which persists after flowers fall off, 10 free stamens, fruits which dehisce along both margins, and shiny red seeds held in the pod for a long time.