Chamaecrista latifolia

Rando, Juliana G., Loeuille, Benoit & Pirani, José Rubens, 2013, Taxonomic novelties in Chamaecrista (Leguminosae: Caesalpinioideae) from Brazil, Phytotaxa 97 (1), pp. 17-25 : 18

Chamaecrista latifolia and C. rossicorum

Chamaecrista choriophylla ( Vogel 1837: 56) Irwin & Barneby (1982: 693) is traditionally subdivided into three varieties: C. choriophylla var. choriophylla , C. choriophylla var. latifolia ( Bentham 1870: 165) Irwin & Barneby (1982: 693) and C. choriophylla var. rossicorum Irwin & Barneby (1982: 693) . We observed that the characteristics used to distinguish them ( Tab. 1; Fig. 1 ) are consistent in all analyzed specimens and in all populations observed in the field. No individuals with intermediate set of these characteristics were found. C. choriophylla var. rossicorum seems to be closely related to C. choriophylla var. latifolia , whereas C. choriophylla var. choriophylla seems to be closer to C. lagotois Irwin & Barneby (1982: 694) , another 2- foliolate species belonging in Chamaecrista series Coriaceae . C. lagotois has similar stems, extrafloral nectaries, form and measure of the stipules, as compared to C. choriophylla var. choriophylla but differs in habit (erect shrub until 2 m high x decumbent shrub until 1 m high) and leaflets shape (strait-elliptical x rhombic). All these taxa are mostly restricted to Serra do Cipó and the Diamantina Plateau in the Espinhaço Range (Minas Gerais state, Brazil, Fig. 2 ). However, they occur in different areas in these regions, except for some collections from Gouveia where these three taxa are found in close proximity according to some collections. This sympatric occurrence has never been observed by us in the fieldwork. During our expeditions we observed that large populations of C. choriophylla var. choriophylla are concentrated to the southwestern side of the Espinhaço Range (Santana de Pirapama area). C. choriophylla var. rossicorum is a very common species in Diamantina Plateau and C. choriophylla var. latifolia is frequently found in South of Espinhaço Range (Santana do Riacho area) and in the Itambé mountain (Pico do Itambé). It is noteworthy to state that these last two places are more humid than the others. Plants of all these taxa grow in the campos rupestres vegetation or in rocky cerrados (a transition from cerrado to campos rupestres), at elevations of 695–1600 m. Only C. choriophylla var. latifolia is also frequently found near to the margins of gallery forests associated with campos rupestres vegetation. We believe that there is strong evidence to recognize three species here and, therefore, two new combinations are proposed. An identification key is also presented aiming to help distinguish the taxa.

Figures

FIGURE 1. Chamaecrista choriophylla: A. Vegetative branch; B. Apex of flowering branch; C. Stipules and D. Petiolar gland. C. latifolia: E. Vegetative branch; F. Apex of flowering branch; G. Stipules and H. Petiolar gland. C. rossicorum: I. Fruiting branch; J. Apex of flowering and fruiting branch; L. Stipules and M. Petiolar gland with ant visitors. Photos Juliana Gastaldello Rando, scale = 1.0 cm.

FIGURE 2. Distribution of Chamaecrista choriophylla, C. latifolia and C. rossicorum.