Zornia decussata Fort.-Perez, G.P.Lewis & A.M.G.Azevedo

Bernal, R., Gradstein, S.R. & Celis, M. (eds.). 2015. Catálogo de plantas y líquenes de Colombia. Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Bogotá. http://catalogoplantasdecolombia.unal.edu.co

Distribution

Nativa en Colombia; Alt. 65 m.; Orinoquia.

Conservation

No Evaluada

Morphology General Habit

Hierba

Fortuna-Perez, A.P., Lewis, G.P. & de Azevedo Tozzi, A.M.G. 2009. Zornia decussata (Leguminosae: Papilionoideae: Dalbergieae), a new species from the Amazon region of Venezuela. Kew Bulletin 64: 719. DOI: https://doi.org/10.1007/s12225-009-9169-4

Type

Venezuela. T.F. Amazonas: Depto. Atures, en la región de Rincones de Chacorro, 11 July 1980 (fl., fr.), Huber 5269 (holotypus K).

Morphology General Habit

Herb, stems prostrate, villous, striate, not branched

Morphology Leaves Stipules

Stipules 7 – 9  ×  3 – 4 mm, ovate-lanceolate, auriculate at the base

Morphology Leaves

Leaves with two leaflets; petioles 4 – 13 mm long, villous, striate; leaflets of lower leaves 4 – 14  × 3 – 9 mm, villous or sparsely so, punctate, ovate to elliptic, apex rounded to acute, base obtuse and oblique, petiolules to 1 mm long, villous; leaflets of upper leaves 7 – 12 × 1.8 – 4 mm, villous, punctate, elliptic to lanceolate (oblong), apex acute, base oblique, petiolules to 0.5 mm long, villous

Morphology Reproductive morphology Inflorescences

Inflorescence spiciform, terminal or axillary, 5 – 11 cm long, villous

Morphology Reproductive morphology Inflorescences Bracteoles

Bracteoles 5 – 7 × 2 – 3 mm, lanceolate to elliptic, 1 – 3-nerved, generally decussate along the inflorescence, upper surface villous, purple-punctate, lower surface sparsely villous to glabrous, translucent-punctate, auricle lacking

Morphology Reproductive morphology Flowers Calyx

Calyx campanulate, 5-lobed, glabrous, margin ciliate, 10 – 11-nerved, tube 3 mm long, vexillary lobes 2, carenal lobes 3, smaller than the vexillary ones

Morphology Reproductive morphology Flowers Corolla

Corolla yellow; standard 6  ×  5 mm, orbicular, apex obtuse, base auriculate, dorsal surface glabrous to pilose at extreme apex, claw 1 mm long, wing petals 5 × 3 mm, ovate, apex rounded, glabrous, keel petals 5 × 2 mm, oblong, apex rounded, glabrous, stamens monadelphous, dimorphic, ovary pilose, style 8 mm long, curved, stigma minute

Morphology Reproductive morphology Fruits

Fruit a loment with 2 – 4 articles; articles 2 × 1.5 – 2 mm, reticulate, sericeous, bristly, bristles to 1.5 mm long, sericeous

Morphology Reproductive morphology Seeds

Seeds 2 × 1 mm, reniform, dark brown, smooth

Distribution

Known from a single collection from the Amazon region of Venezuela.

Ecology

In shrubby savanna on sandy soil; 80 m.

Conservation

Zornia decussata is known from a single collection in an area that is known to be well-collected; although the field label describes the species as being locally common its conservation status is currently considered to be Data Deficient (DD).

Phenology

The only known collection (in flower and fruit) was made in July.

Note

The new species is uniquely diagnosed by its decussate bracteoles. Zornia decussata can be readily distinguished from all other species of Zornia by its decussate pairs of bracteoles, a unique characteristic within the genus, and by the unique cataphylls between the stipules; it is distinct within sect. Anisophylla by its delicate habit. Among the species of Zornia sect. Anisophylla, the new species is similar to Z. microphyllaDesv. in having prostrate stems and elliptic-lanceolate 1 – 3-nerved bracteoles. Z. microphylla has, however, highly branched, glabrous stems and bracteoles that are not decussate along the inflorescence. Another Venezuelan species that has a delicate habit is Z. herbaceaPittier, but this differs in having markedly branched stems, epunctate 6-nerved bracteoles with auricles to 3 mm long, and articles of the lomentaceous fruit not reticulate-veined. Z. decussata could be confused with Z. curvataMohlenbr., which has similarly shaped bracteoles and with Z. latifolia, which also lacks auricles on most bracteoles. However, Z. curvata differs in having a decumbent habit, branched stems and the auricle of the bracteoles at least 1 mm long, and Z. latifolia generally has larger, linear bracteoles, and is a subshrub with a branched habit.

Distribution

Biogeografic region: Orinoquia. Elevation range: 65–65 m a.s.l. Native to Colombia. Colombian departments: Vichada.

Habit

Herb.