History Linnaeus, in formally describing the genera, placed
Theophrasta and related genera in a group he named
Pentandria Monogynia (i.e 5
stamens, one
pistil), his system being based on sexual characteristics.
Jussieu arranged Linnaeus' genera in a
hierarchical system of ranks based on the relative value of a much wider range of characteristics. In his
Genera plantarum (1789) he organised the primuloid genera into two
Ordo (
families), within a
class (VIII) he called
Dicotyledones Monopetalae Corolla Hypogyna, based on the
cotyledons (two), form of the petals (fused), and position of the
corolla with respect to the
ovary (below). Jussieu's families were the Lysimachiae, including
Primula and
Theophrasta and the
Sapotae, including
Myrsine, these being the three main lineages in modern understanding of the
Primulaceae.
Don described a family of Theophrasteaceae in 1836, with four genera,
Theophrasta,
Clavija,
Jacquinia and
Leonia, of which the latter was determined unrelated, and placed this family as closely related to Myrsineae and Sapoteae. Later,
De Candolle more formally described a family, Theophrastaceae, based on the genus
Theophrasta, in 1844, with six genera,
Theophrasta,
Clavija,
Jacquinia,
Oncinus,
Monotheca and
Reptonia. The latter three are no longer considered related. Theophrastaceae were included in the order
Primulales by
Cronquist (1988). The
APG system (1998) submerged that order in an enlarged order
Ericales (Ericales
s.l.), a
basal group in the
asterids, where the families of Primulales formed a
monophyletic primuloid
clade. Subsequent
molecular phylogenetic analysis showed that the genus
Samolus (brook weeds), with about 12–15 additional species and traditionally placed within Primulaceae, as
tribe Samoleae, was more closely related to the Theophrastaceae and suggested its transfer. Briefly
Samolus was considered a separate family, Samolaceae. The third revision of the APG,
APG III (2009) realigned all the primuloid families within a greatly enlarged Primulaceae (Primulaceae
s.l.), in which each of the existing families became a subfamily. The newly described Theophrastoideae included
Samolus, vastly increasing the area of distribution.
Phylogeny The
cladogram below shows the infrafamilial phylogenetic relationships of Primulaceae, together with the subfamilial
crown ages. Maesoideae forms the basal group, while Primuloideae and Myrsinoideae are in a
sister group relationship.
Subdivision The phylogenetic relationships of the 8 accepted genera are shown in the cladogram, in which
Samolus forms the basal group and is sister to all other Theophrastoideae (Theophrastaceae
s.s.), the remaining genera forming two subclades. Alternatively these two subclasses have been designated as two tribes, Samoleae and Theophrasteae: |1=
Jacquinia L. |2= }} }} }} }} }} }} The Theophrasteae consist of seven genera and about 100 species, while Samoleae has only the single genus
Samolus, with about 12–15 dozen species. In 1903, Theophrastaceae consisted of four genera,
Clavija,
Jacquinia,
Deherainia, and
Theophrasta. In 1904, a species of
Deherainia was
segregated to form the novel genus
Neomezia, to create five genera and in 1993 a species of
Jacquinia was segregated to form a sixth genus,
Votschia. Molecular phylogenetic analyses revealed that
Jacquinia was still
paraphyletic consisting of two separate and distinct clades, necessitating splitting off another new genus,
Bonellia, to make seven genera in total in this tribe.
Etymology Theophrastoideae takes its name from the nominative and type genus, Theophrasta, named by Linnaeus after the Ancient Greek philosopher and biologist
Theophrastus. == Botanical authority ==