Trischidium decipiens (A.Lyons) H.E.Ireland

Ireland, H. (2007). Taxonomic Changes in the South American Genus Bocoa (Leguminosae-Swartzieae): Reinstatement of the Name Trischidium, and a Synopsis of Both Genera. Kew Bulletin, 62(2), 333-349. Retrieved from http://www.jstor.org/stable/20443359

Type

Brazil, Pernambuco, Araripina, Campos da serra do Araripe, proximos a Estação Experimental, 24 June 1952, A. Lima and M. Magalhães 52-1075 (holotype US!; isotypes IPA, R!).

Morphology General Habit

Shrub or tree 1.4 - 2 m tall, flowering and fruiting with the leaves

Morphology Stem

Young branchlets shortly pubescent, older branchlets glabrescent

Morphology Leaves

Leaf rachis 11 - 40(76) mm long, shortly pubescent, sometimes channelled above; petiole 1 - 9 mm long; leaflets (5) 7 - 9 (11), elliptic to obovate, the lower pair often rounded, apex obtuse to rounded, glabrous, with a few hairs on the midvein above, glabrous beneath, terminal leaflet largest, 10 - 42 mm long, 5 - 19 mm wide, lateral leaflets 3.5 - 37 mm long, 3 - 18 mm wide; sessile or with petiolule up to 0.5 mm long, 0.5 - 1 mm wide, pubescent

Morphology Reproductive morphology Inflorescences

Inflorescence axillary, the axes either single or in pairs, 1 - 2 mm long, the axis shortly pubescent; floral bract 0.5 - 1 mm long, deltoid, persistent or caducous in fruit, pedicel 7 - 10.5 mm long, sparsely strigose

Morphology Reproductive morphology Flowers

Flower only seen in bud, calyx glabrous internally, shortly and sparsely pubescent externally, caducous before fruiting; petal absent; stamens 8 - 10, anthers 3- 3.5 mm long, base sub-auriculate, filaments c. 1 mm long; ovary and immature fruit densely white pubescent, style glabrous, 2 - 3 mm long, persistent in fruit

Morphology Reproductive morphology Fruits

Fruit body 8 - 15 mm long excluding remnants of the style, 7 - 9 mm wide, 5 - 6 mm broad, strigose to pubescent, the stipe 1 - 2 mm long

Morphology Reproductive morphology Seeds

Seed ellipsoid, red, drying dark brown to black, 4- 6.5 mm long, 3.5 - 5 mm wide, 3 - 4.5 mm deep.

Distribution

Brazil (Amazonia, Bahia, Ceará, Pernambuco). One specimen at Kew (Drysdale s.n.) is recorded from Paraguay, but there is no further location data.

Ecology

Cerrado or open woodland on sandy soil.

Phenology

Flowering time: April to Aug.

Note

This is the only species of Trischidium without a petal, a character that has never before been noted. The inclusion of this species in Trischidium is justified because it conforms to all other generic characters. Such plasticity is common within basal papilionoid legume genera. For example, petal and stamen number is variable within Ateleia (Ireland, 2001), Swartzia (Cowan, 1968), and Bocoa ratteri H. E. Ireland, and some species of Swartzia (Cowan, 1968) sometimes have two free carpels. Petal presence or absence is also a variable character amongst the basal papilionoids. For example, Ateleia and Cyathostegia, the two most closely related genera to Trischidium, always possess a petal, whereas all species of Bocoa sensu stricto and some species of Swartzia lack a petal. Open flowers of this species have not been seen, and the floral parts in the illustration are drawn from bud dissections. Cowan (1974) remarked that this species is closest to T. molle because of the similar leaflet shape and number. It appear-s to resemble T molle more than any other Trischidium species, and is probably its closest relative. It differs, however, because of its smaller leaflets, shorter rachis, densely pubescent ovary and lack of a petal. The proposal by Holmes (1896) that this species "...might be provisionally named Swartzia decipiens", does not meet the requirements of the International Code of Botanical Nomenclature (Greuter et al., 2000, article 34.1) for a validly published name, which states that "a name is not validly published… when it is merely proposed in anticipation of the future acceptance of the group concerned...". The combination of this species in Tounatea by Lyons (1907), based on this name, is therefore also invalid. Cowan (1974) provided a Latin diagnosis and English description for this species in Bocoa and chose to retain Holmes' (1896) choice of species epithet. From the Latin 'decipiens' meaning to deceive. Some 200 years ago importations of Pilocarpus microphyllus Stapf (Rutaceae) leaves from Brazil to Europe for medicinal purposes were found to contain some leaves that looked almost identical to Pilocarpus, except they did not yield pilocarpine. E. M. Holmes of the Pharmaceutical Society in London suggested that they belonged to a new species of Swartzia and that "the plant might be provisionally named Swartzia decipiens" (Holmes, 1896). It was not until 1974, that this species was described in Bocoa (Cowan, 1974) using this epithet.

International Legume Database and Information Service

Conservation

Insufficiently known

Morphology General Habit

Perennial, Not climbing, Shrub