Is it Lacistemaceae Mart. or Lacistemataceae Mart.?
To find out which is correct a historical analysis of the family name and genera is essential.
The genus name Lacistema dates from 1788 with the naming of Lacistema myricoides by Olaf Swartz in his book entitled Nova Genera & Species Plantarum seu Prodromus descriptionum vegetabilium, maximam partem incognitorum quae sub itinere in Indiam Occidentalem annis 1783-87.
As you can see from the protologue below Swartz has renamed Piper aggregatum as Lacistema myricoides as he must have decided the flowers bear no morphological similarity to Piper species.
In 1810, genus Lozania Mutis ex Caldas is discovered by Jose Celestino y Mutis but he dies before he can publish this new species, so the species is published in the paper Semanario del nuevo Reyno de Granada by his successor Francisco Jose de Caldas but decades before an evolutionary association is made with Lacistema.
The Lozania protologue below (still tracking down the original book) is taken from Art. XII. Botanical Extracts from a Periodical Miscellany published in Spanish at Santa Fe de Bogota, entitled "E Semanario del Nuevo Reyno de Granada" 1810 (1817) in Journal of Science and the Arts, John Murray, London: Vol III: 125-6
In 1826 the family name Lacistemaceae and protologue (below) appear in Nova genera et species plantarum quas in itinere per Brasiliam annis 1818-1820 by Dr. Carl F P de Martius. Hence the name: Lacistemaceae Mart.
But the name Lacistemaceae is incorrect as it is inconsistent with the rules of botanical Latin (Stearn 2004). Any neuter noun of Greek origin ending -ma as in Lacistema becomes -mata, thus the correct name for the family is Lacistemataceae. With my discovery on 08 October 2008 that Lacistema is of Latin and not Greek origin Lacistemaceae ought be the correct name. However, the International Code of Botanical Nomenclature (ICBN) have placed nomen conservandum on the family name and therefore officially remains as Lacistemataceae.
The first correct usage of the name Lacistemataceae does not appear in plant classification until 1959 in Die Evolution der Angiospermen by Armen Takhtajan.
Sleumer (1980) placed Lacistemataceae in Flacourtiaceae as tribe Lacistemeae, but the Angiosperm Phylogeny Group have since returned Lacistemataceae to a family in its own right. Morphological and genetic research is ongoing as to whether Lacistemataceae ought to be incorporated into Salicaceae or remain a family in its own right.
Lacistema protologue images courtesy of Biodiversity Heritage Library. A symbiotic project by 10 internationally recognised institutions to digitize rare scientific books for all to read and enjoy.
International Code of Botanical Nomenclature (Vienna Code 2005) (ICBN) online and Regnum Vegetabile 146, A.R.G. Gantner Verlag KG, Vienna
Sleumer H O (1980) Flora Neotropica: Monograph Number 22 - Flacourtiaceae, The New York Botanical Garden, New York: 182-206
Stearn W T (2004) Botanical Latin, Timber Press Inc., Oregon: 61
Stevens P F (2001 onwards) Angiosperm Phylogeny website, Version 9, June 2008