Ximeniaceae Horan

Genera Included: Curupira Black, Douradoa Sleumer, Malania Chun & Lee., and Ximenia L

Habit: Evergreen trees and shrubs (some Ximenia).

Parasitism: Ximenia is a root hemiparasite (DeFilipps 1969), however, the trophic status of the other three genera has not been established. Given the support for the Ximeniaceae clade on the molecular tree, it is likely that all are parasitic.

Roots: the root system with haustorial attachments to its host (cultivated Pelargonium) are illustrated in DeFilipps (1969). 

Stem: twigs generally glabrous. Buds in Malania covered with gray-brown pubescence. All genera form long-shoots but in Ximenia, two kinds of short-shoots are present: those in the leaf axils which form spines and vegetative spur-shoots that form at the bases of the spines.

Leaves: alternate, simple, entire, without stipules; chartaceous (Curupira) to coriaceous; glabrous (Curupira, Douradoa) or pubescent; basalmost lateral vein acrodromous (Curupira, Douradoa) and excurrent along margin or camptodromous (eucamptodromous to slightly brochidodromous); petiole canaliculate, proximal and distal portions swollen or not.

Leaf anatomy: epidermal cells not lignified; guard cells not lignified, lumina narrow or wide, cuticular ledges inconsipuous or thick;  paracytic stomata absent or present, cyclocytic and anisocytic stomata absent;  schizogenous cavities, laticiferous channels and druses absent; silicified walls of mesophyll and epidermal cells present;  mesophyll sclereids and leaf cystoliths absent;  petiole and median vein slerenchyma fibers absent;  petiole and median vein astroslereids present; vascularization of the nodes trilacunar;  basal petiole vascularization an incomplete vascular cylinder, distal petiole vascularization a simple bundle, median vein vascularization a simple bundle.

Wood anatomy: vessels grouped in multiples; perforation plate type scalariform; vessel members over 900 µm in length; intervascular pits alternate; vascular tracheids assoc. w/ vessels absent or present;  fibers as fiber tracheids;  axillary parenchyma frequency abundant and rare or absent; axial parenchyma strand less than 7 cells wide;  ray type heterocellular, with one row of erect cells;  ray height above and below 1000 µm;  wood cystoliths absent; silica bodies in ray cells absent.  

Inflorescence: axillary pedunculate umbels. In Malania, the umbel is compound, composed of 2-3 umbels clustered in a short raceme (derived from short-shoot?). In Ximenia, in addition to simple umbels, subumbellate cymes, 2-10 flowered fascicles or solitary flowers may be present. Bracts present at junction of peduncle and pedicel in Douradoa (and some Ximenia). The peduncle is glandular at the apex in Curupira and Douradoa.

Plant Sex: flowers bisexual or in Ximenia parviflora, functionally bisexual or unisexual (DeFilipps 1969).

Flowers: 4-merous (to 5-merous in Ximenia)

Fruit: drupes, variously shaped (pyriform, sub-globose, oblong); endocarp woody or crustaceous.

Seed: endosperm oily; seeds of Malania valued for their commercially useful oils (acetylenic fatty acids). 

Chromosomes: Chromosome numbers have been reported for Malania (Yang & al., 2003): n = 13; Ximenia (Robertson, 1982; Hunziker & al., 1985): n = 13, 26. Kondo & al. (1981) reported slightly different numbers for that species: n = 12, 24.

Alternate Family Names: none.

SIUC / College of Science / Parasitic Plant Connection / Olacaceae / Description
URL: http://www.parasiticplants.siu.edu/Olacaceae/description.html
Last updated: 27-Oct-10 / dln