This paper consists of the descriptions of various new species and varieties, a new genus Moacroton from Cuba, and critical notes and records, reductions, and transfers. Unless otherwise stated, the types of the forms herein described are preserved in the herbarium of the Arnold Arboretum.Phyllanthus Linnaeus Phyllanthus vichadensis sp. nov.Fruticulus caules strictos plures erectos e rhizomate perenni edens, ramis glaberrimis exalatis subexalatisve. Foliis ellipticis carnosulis enerviis 5-7 mm. longis, 2 mm. latis, utrinque aequo iure acuminatis petiolulo ca. 1 mm. longo, stipulis subsetaceis integris ca. 2 mm. longis. Floribus secus apicem ramulorum dispositis, £ ad 3 capitulatim aggregatis subsessilibus, 9 longius pedicellatis saepissime singulis. Perianthio S ca. 2 mm. longo 2.5 mm. lato 5-lobo, antheris 3 in columna ca. 1.5 mm. alta coalitis longitudinaliter dehiscentibus, columna basi incrassata revera haud glandulosa. Perianthio 9 magnitudine fere 6 5-lobo, lobis costatis rotundato-ellipticis, disco nullo subnullove, ovario globuloso depresso ca. 1 mm. in anthesi magno, stylis 3 ca. 1 mm. longis e basi liberis subliberisve apice bilobato partitis, pedicello sub fructu nonnihil apice incrassato ad 4 mm. longo.Colombia: Comisaria El Vichada: About 70 km. southeast of Orocue, Haught 2779. This new species is described as an inconspicuous perennial of the open llanos. Its habit is reminiscent of P. diffusus Kl., an annual weed with which it was originally confused in the herbarium. Fragments of Lepricur 319 and Schomburgk 529 in our herbarium show that it definitely differs from P. hyssopijolioides H. B. K. (well represented by Williams 15945a; Venezuela, Amazonas, Puerto Ayacucho) and P. guianensis Kl. in foliage as well as in floral characters. It may be remarked that the habit and gross morphology of the latter is reminiscent of the species in the vicinity of P. caroliniensis Walt.Frutex lignosus innovationibus pallide ochraceis velutino-hispidis dcmiiin glabratis. Foliis pro more ovatis, interdum lanceolatis vel oblongo-ovatis. 5-8 cm. longis, 2-5 cm. latis, olivaceo-brunneis vel brunneis, submembranaceis, subtus laxius stellato-pubescentibus subgriseis, supra pilis subsimplicibus more proprio adpressis setoso-pubescentibus, apice breviter acuminatis, basi rotundatis vel leviter cuneatis, margine subintegris ciliatis, nervis adscendentibus ca. 7-9-jugis, primo jugo ramoso, glandulis stipulisque
