Cleobulia Mart. ex Benth., Comm. Legum. Gen.: 67. 1873.

Queiroz, Luciano Paganucci de & Snak, Cristiane, 2020, Revisiting the taxonomy of Dioclea and related genera (Leguminosae, Papilionoideae), with new generic circumscriptions, PhytoKeys 164, pp. 67-114 : 67

3. Cleobulia Mart. ex Benth., Comm. Legum. Gen.: 67. 1873.

Type.

Cleobulia multiflora Mart.ex Benth. [= Cleobulia coccinea (Vell.) L.P. Queiroz]

Description.

Woody vines. Stipules basifixed, not prolonged beyond their base. Leaves pinnately trifoliolate, the rachis reduced, sometimes absent, stipellate. Inflorescence a pseudoraceme, arcuate, nodes multiflorous, sessile, globose, secundiflorous; bracteoles fleshy. Flowers resupinate because of the arching inflorescence; calyx fleshy, cylindrical, the 4 lobes much shorter than the tube, upper lobe truncate to slightly emarginate, lower lobe triangulate and acute; petals firmly chartaceous, pink to purple, standard petal spreading or reflexed, ecallose, provided with two basal and reflexed auricles, pubescent towards the apex on the outer surface, wing petals dwarf, ca. 1/3 of the keel length, sagittate, keel petals upcurved with truncate apices; androecium pseudomonadelphous, staminal tube pubescent at the base, anthers monomorphic, all 10 stamens fertile; intrastaminal nectary disc 10-lobed; pistil straight then upcurved ca. 90° in the middle, ovary 6-8-ovulate, sessile, style not swollen. Fruits linear-oblong, 3-5 × longer than wide, elastically dehiscent, the thin woody valves explosively twisting to release the seeds, upper margin straight to undulate, with thin ribs. Seeds small, under 10 mm long and 6 mm wide, lenticular (slightly biconvex); testa hard (bony), smooth; hilum linear encircling almost half of the seed’s circumference (Fig. 2A-D ).

Discussion. Since first being described, Cleobulia was distinguished from Dioclea by having dwarf wings with a semi-sagitate blade ( Bentham 1837; see Fig. 2B ). Cleobulia could likewise be diagnosed by having an inflorescence with a long and arching peduncle, leaving its flowers resupinate (i.e. with the standard petal in a lower position and the keel above), a pseudomonadelphous androecium, the base of the staminal tube pubescent, with uniform anthers, a 10-lobed intrastaminal disc, and a sessile and straight ovary.

Three species are found from eastern Brazil to the eastern Brazilian Amazon and one species from western-central Mexico, all mostly in semi-deciduous forests.

Figures

Figure 2. Representatives of the clade A. Cleobulia coccinea (Mart. ex Benth.) L. P. Queiroz A flowering vine showing the arcuate inflorescences B detail of the inflorescence showing resupinate flowers; the inset highlights the wing petals (w) much shorter than the standard (s) and keel petals (k) C fruit (from Queiroz 16029). Cleobulia diocleoides Benth. D a resupinate flower showing the reduced wing (from Queiroz 16036). Cymbosema roseum Benth. E part of the inflorescence showing the bird pollinated flowers and the free adaxial stamen (arrow) F immature fruits showing the characteristic broad oblong fruit body and the long beak (from Cardoso 2868). Dioclea virgata (Rich.) Amshoff G flowers (from Cardoso 2374) H fruits (from Cardoso 2100). Dioclea fimbriata Huber I flowers (from Snak 1223). Dioclea burkartii R. H. Maxwell J a seed showing the marbled testa and the elongate hilum encircling about half of its circumpherence (arrow; from Snak 826). Dioclea apurensis K flowers (from Queiroz 13035). Photos A-D, J-K: L. P. Queiroz; E-H: D. Cardoso; I: C. Snak.