Stegnospermataceae

Stegnospermataceae

Introduction

A monogeneric family with three species occurring from northwestern Mexico to Nicaragua and the Antilles (Rohwer 1992). The family includes small trees and shrubs characterised by bisexual flowers with two-whorled perianth, one whorl consisting of five free, green sepals, and the other of five white petals with narrow base, which are adherent to the alternisepalous stames at the base. The fruits are capsules and the seeds are arillate (Rohwer 1993).
When the only genus Stegnosperma Benth. was described in 1844, it was placed in Phytolaccaceae and accepted by other authors (e.g. Heimerl 1934). Nakai (1942) elevated the genus to the family level. Recognition as a family was also supported by morphological, palynological, and wood anatomical characters (e.g. Nowicke 1969; Bell 1980; Carlquist 1999). For a detailed taxonomic history until the 1980s see Bell (1980).
The early molecular phylogenetic studies of Downie & al. (1997) and Fay & al. (1997) showed the position of Stegnosperma as an independent lineage. However, both classifications, the recognition of Stegnospermataceae (e.g. Rohwer 1993; Takhtajan 1997) and Stegnosperma within Phytolacacceae (e.g. Stevens 2001) continued to be used. Subsequent phylogenetic studies (e.g. Savolainen & al. 2000; Cuénoud & al. 2002; Schäferhoff & al. 2009; Qiu & al. 2010; Brockington 2009, 2011; Soltis & al. 2011) confirmed the findings of Downie & al. (1997) and Fay & al. (1997), resulting in the wide recognition of Stegnospermataceae as a separate family.

Synonymy

Stegnospermataceae Nakai in J. Jap. Bot. 18: 108. 1942 sec. APG III (2009)