Calliandropsis H.M. Hern. & P. Guinet, Kew Bull. 45(4): 609. 1990.

Figs 144, 145, 146, 157

Type.

Calliandropsis nervosa (Britton & Rose) H.M. Hern. & P. Guinet [≡ Anneslia nervosa Britton & Rose]

Description.

Small, unarmed shrubs to 1 m, profusely and intricately branched from the base (Fig. 144J); brachyblasts present, densely covered with persistent imbricate stipules, bearing leaves and inflorescences. Stipules leafy, triangular, to 2 mm. Leaves bipinnate; a cupular nectary at the point of insertion of the pinnae; pinnae 1 pair; leaflets (5) 6-9 (11) pairs per pinna, opposite, oblong, oblique at the base, acute at the apex, glabrous or sparsely villous with prominent primary and secondary veins abaxially. Inflorescences compact semi-spherical capitula, solitary in the axils (Fig. 145H), on a short peduncle, subtended by triangular bracts. Flowers usually all hermaphrodite but sometimes with a few functionally staminate flowers proximally; sepals valvate in bud, connate, calyx campanulate, 5-lobed; petals 5, valvate in bud, free or fused, lobes oblanceolate; stamens 5 per flower, all fertile, white or pale pink, anthers mostly eglandular, rarely with a minute sub-cylindrical apical gland; pollen in tricolporate monads; ovary sericeous, sessile, 5-6-ovulate, stigma tubular. Fruits dry, non-septate, straight, plano-compressed, oblanceolate, 1-5-seeded, the margins thickened, apex acute, valves rigidly coriaceous, dehiscing elastically from the apex to the base without twisting, the valves strongly recurving and persistent after dehiscence (Fig. 146N). Seeds ovoid, dark brown, pleurogram U-shaped.

Chromosome number.

Unknown.

Included species and geographic distribution.

Monospecific ( C. nervosa), endemic to central Mexico from Durango south to Oaxaca (Fig. 157).

Ecology.

Seasonally dry thorn scrub on dry rocky calcareous soils, 1450-2000 m elevation. Seed dispersal mechanical via elastically dehiscent pods. Deciduous.

Etymology.

From Greek, - opsis (= appearance), referring to the resemblance to (the fruits of) the genus Calliandra .

Human uses.

Unknown.

Notes.

Calliandropsis is robustly supported as sister to the rest of the Dichrostachys subclade (Fig. 143), presenting a striking amphi-Atlantic disjunction between dry central Mexico and the Old World, mainly Madagascan, Dichrostachys, Gagnebina and Alantsilodendron clade. Fruiting specimens of Calliandropsis are often mis-identified as Calliandra eriophylla Benth., which co-occurs with Calliandropsis in south-central Mexico, because of the strong similarity of its elastically dehiscent fruits to those of Calliandra, but the flowers of Calliandropsis, with few free stamens, immediately distinguish it from Calliandra which has flowers with numerous stamens fused into a tube.

Taxonomic references.

Hernández and Guinet (1990), including an illustration.