Commelina congestispatha Lopez-Ferr., Espejo & Ceja

Commelina congestispatha López-Ferr., Espejo & Ceja Commelina congestispatha López-Ferr., Espejo & Ceja (López-Ferrari et al. 2009: 72–75, fig. 1). Etymology The epithet derives from the combination of the Latin ʻ congestī ʼ (meaning ʻclustered, togetherʼ) + the Ancient Greek ʻ σπάθη ʼ (spáthē, meaning ʻany broad bladeʼ), in reference to this species’ very dense synflorescences composed of several spathes (i.e., inflorescences). Type material MEXICO – Guanajuato • Cuerámaro, 1.2 km después de Canãda de Corralejo, rumbo a la barranca de El Chilar; 4 Sep. 2006; fl., fr.; A. Espejo et al. 6903; lectotype: UAMIZ [UAMIZ0068668]!, designated here; isolectotypes: CIIDIR n.v., IBUG n.v., IEB [IEB0233919]!, QMEX n.v., UAMIZ [UAMIZ0068663]!, [UAMIZ0068671]!, UJAT n.v. Remarks Commelina congestispatha has been recently reduced to a synonym of C. robusta (as C. obliqua; Hassemer 2019). Despite the plant’s gross morphology resembling C. robusta, C. congestispatha is indisputably more closely related to C. erecta due to its auriculate leaf-sheaths, leaf-blades with red to vinaceous margin, vestigial and flowerless upper cincinnus, lower sepals completely connate and cup-shaped, hyaline and involute medial petal, capsules with verrucose dorsal valve, and appendaged seeds with smooth testa (Lopez-Ferrari et al. 2009; Pellegrini, pers. obs.). Nonetheless, the number of inflorescences congested at the stems’ apex [i.e., 3–10 florescences per synflorescence C. congestispatha vs 1(–3) in C. erecta], the posture of the paired petals (in an obtuse angle to almost in the same plane to each other vs in an acute angle to each other, commonly partially overlapping), the length of the paired petals’ claw (1–1.5 mm vs 3–8.5 mm long), the length of the paired petals’ limb (6.7–7.2 mm long vs 11–23 mm long), and the shape of the antherodes (lobes subrotund vs spathulate) undoubtedly supports both species as distinct. Thus, we reestablish C. congestispatha as a Mexican endemic, closely related to C. erecta.