Common Name: STEMSUCKER FAMILY
Habit: Perennial herb? (duration of plants uncertain), stem parasites, non-green (chlorophyll 0), dioecious? (number of plants contributing to flowers observed on given host uncertain). Stem: reduced, thread-like, inside host stem. Leaf: simple, bract- and/or scale-like, 2--6, subtending flower, generally in 2 series. Inflorescence: flower 1. Flower: unisexual, radial, fleshy; sepals 4--5, often fused at base; petals 0; stamens many, generally fused to style to form column that is expanded at tip into disk or knob (column, disk completely of carpels in female flowers according to Blarer et al.); anthers or stigmatic hairs on column, below disk margin; ovary +- inferior, chamber 1, placentas parietal. Fruit: berry-like, +- fleshy, generally dehiscing irregularly in age. Seed: many, minute.
Genera In Family: +- 2--3 genera, +- 12--20 species: southwestern United States to South America, eastern Africa, southwestern Asia, western Australia. Note: Poorly known taxonomically, ecologically, reproductively. Molecular evidence (Blarer et al., and online references) indicates Rafflesiaceae, in which our plants were included in TJM (1993), are polyphyletic, consisting of 3 main lineages belonging to different orders, evidently Malvales or Cucurbitales for our pls.
Unabridged Note: Morphological and molecular evidence (Barkman et al., 2004; Blarer et al. 2004, Nickrent et al., 2004; Davis et al., 2007) has established that the traditional broadly circumscribed Rafflesiaceae are polyphyletic, consisting of three or four main lineages belonging to different orders. Rafflesia and related, large-flowered, Old-World, stem and root parasites of Vitaceae are presently considered to be members of the Malpighiales and either sister or basal to members of the Euphorbiaceae. Mitrastema, with two disjunct, medium-flowered species of the Old and New World tropics that are parasitic on the roots of Fagaceae, is now classified in the Mitrastemonaceae in the Ericales. The two genera of Cytinaceae, the neotropical Bdallophytum (two species, root parasites of Burseraceae) and Cytinus (about eight species, root parasites on various host taxa), appear to be related to the Malvales. The phylogenetic placement of Apodanthaceae, with 2 or 3 genera in both the Old and New World that have small flowers and are stem parasites on Fabaceae and Salicaceae (Flacourtiaceae), remains unresolved, but apparently involves either the Malvales or Cucurbitales.
eFlora Treatment Author: George Yatskievych
Scientific Editor: Thomas J. Rosatti.