Taxonomic and nomenclatural notes on neotropical Commelina (Commelinaceae), and an identification key for Brazil, Guyana, Paraguay, Suriname and Uruguay Author Hassemer, Gustavo text Phytotaxa 2017 2017-04-11 303 2 101 117 http://dx.doi.org/10.11646/phytotaxa.303.2.1 journal article 10.11646/phytotaxa.303.2.1 1179-3163 13687569 7. Commelina schomburgkiana Klotzsch ex Seubert (1855: 262) Holotype : GUYANA . R . H . Schomburgk 490 (B-100247302! [ Fig. 7 ]; isotype K-000363254!). Commelina schomburgkiana var. latifolia Klotzsch ex Schomburgk (1849: 1064) , nom. inval. (Arts. 35.1 and 38.1; see also Art. 38.3) Distribution: —Confirmed occurrences in Guyana (where the type originated from), Paraguay and southern Brazil . Habitat: —Open areas, particularly forest edges. FIGURE 5. Lectotype of Commelina rufipes ( C.F.P. von Martius s.n. , M-0210921). Published with permission of Botanische Staatssammlung München. FIGURE 6. Holotype of Commelinopsis glabrata ( W.E. Broadway 6716 , K-000363259). Published with permission of Royal Botanic Gardens, Kew. Available online at: http://specimens.kew.org/herbarium/K000363259. FIGURE 7. Holotype of Commelina schomburgkiana ( R.H. Schomburgk 490 , B-100247302). Published with permission of Botanischer Garten und Botanisches Museum Berlin-Dahlem. Available online at: http://herbarium.bgbm.org/object/B100247302. Conservation status: —Least Concern (LC). This species has a wide distribution in South America and does not seem to be threatened. Notes: —The authorship of C. schomburgkiana has been erroneously presented in recent literature such as Barreto (1997) , Zuloaga et al. (2008) and Hassemer et al. (2016b) , and databases such as IPNI (http://www.ipni.org) and Tropicos (http://tropicos.org). The taxonomic status of C. schomburgkiana , which is part of the C. diffusa group, has until now been confusing because the only reliable character to distinguish it from the latter species is leaf shape; linear-lanceolate in C. schomburgkiana , ovate to elliptic in C. diffusa . However, I discovered another taxonomically informative character. The flowers of C. schomburgkiana have three white and blue staminodes ( Fig. 8 ), whereas those of C. diffusa have two yellow staminodes.