Ctenolophonaceae

Description

Trees. Tufted hairs present. Leaves opposite. Stipules interpetiolar. Flowers hypogynous. Petals caducous, contorted. Fruit a capsule. Seed persistent on the columella after the valves have been shed, with hairy-papillose arillode.

Taxonomy

The systematic place of the tropical lowland rain-forest tree Ctenolophon OLIVER has a chequered history.

Originally it was referred to affinity with Olacaceae (OLIVER, 1873; MASTERS, 1875; ENGLER, 1889; BAILLON, 1892) or Icacinaceae (BECCARI, 1877). HALLIER.f. (1912, 1918) held another view and arranged the genus in the Celastrales, deriving this group from Linaceae. HUTCHINSON (1959, 1973) referred the genus to the Malvales.

In a meticulous exposé of the anatomy, flower and fruit structure, PIERRE (1893) concluded that the affinity of Ctenolophon is with the Linaceae and he was followed by ENGLER (1907), EXELL (1927), and HUB.WINKLER (1931).

At present Ctenolophon is almost unanimously recognized as belonging to the Linaceous affinity, together with Ixonanthaceae. Within Linaceae HUB.WINKLER (1931) had raised the gen
us to the rank of a monogeneric subfamily. Later EXELL & MENDONÇA (1951) recognized it as representing a family of its own, a view now almost unanimously accepted, as fully discussed by VAN HOOREN & NOOTEBOOM (1984).

In the treatment of the family Linaceae (page 607, see there) the families Linaceae, Ixonanthaceae, and Ctenolophonaceae are opposed by concise diagnoses.

On account of studies of special features some other affinities have been put forward. HEIMSCH (1942) found a remarkable resemblance in xylem structure with Humiriaceae. CRONQUIST (1981) referred to Ctenolophon as an aberrant member of Hugoniaceae, a view with which we cannot agree. VAN WELZEN & BAAS (1984) compared the leaf anatomy of Ctenolophon with that of Hu-miria and some Malpighiaceae and found that it is very different from both Humiriaceae and Malpighiaceae, but also from other Linaceae, and they supported the status of a family of its own, adding that close affinities are still unknown.

Synonymy

Ctenolophonaceae