Balanophoraceae

Genera Included: Balanophora, Chlamydophytum, Corynaea, Ditepalanthus, Exorhopala, Helosis, Langsdorffia, Lathrophytum, Lophophytum, Ombrophytum, Rhopalocnemis, Sarcophyte, Scybalium, Thonningia. Takhtajan (1987) split Balanophoraceae into six families: Mystropetalaceae, Dactylanthaceae, Lophophytaceae, Sarcophytaceae, Scybaliaceae, Helosaceae [as Helosidaceae], Langsdorffiaceae, and Balanophoraceae. Molecular evidence has shown that three families exist here: Cynomoriaceae (in Saxifragales), Mystropetalaceae (in Santalales) and Balanophoraceae (in Santalales). 

Habit: Fleshy, achlorophyllous holoparasites

Parasitism: Attaching to roots of trees and shrubs (rarely herbaceous plants) by a structure called a tuber which may contain only parasite tissue or mixtures of host and parasite. Plants often accumulating a waxy product called balanophorin.

Roots: The slender rhizomes (roots?) grow from the tuber and form haustorial connections to the host roots they encounter.

Stem: Absent (aerial portions technically an inflorescence)

Leaves: Scaly, without stomata, spirally arranged

Inflorescence: Inflorescence bearing "stems" arise endogenously within the tuber. Branches subtended by scaly, reduced, caducous bracts, which in some genera are peltate or in others triangular or clavate.

Plant Sex: Plants monoecious or dioecious

Flowers: Often minute and numerous - some of the smallest flowers in the angiosperms. Unisexual, monochlamydous, entomophilous.
Calyx: Staminate flowers diverse with 3-4 (-8) distinct or basally connate, valvate tepals with a stamen opposite each tepal.
Corolla: Absent
Androecium: With a tetrasporangiate, dithecal anther opening by longitudinal slits. Stamens often very reduced, monothecal anther opening by a terminal pore, sometimes coalescent to form a synandrium opening irregularly from bilocular, rarely trilocular numerous transverse slits.
Pollen: 3-5 colpate or 3-many-porate or inaperturate, variously binucleate or trinucleate, the binucleate types associated with a wet stigma, the trinucleate ones with a dry one.
Gynoecium: Carpellate flowers lacking a perianth. Gynoecium of 2 or 3 carpels united to form a compound ovary with (2-3) distinct styles or a single trifid style or sometimes the stigma sessile and discoid, or in Balanophora the gynoecium pseudomonomerous and with a single undivided style. Ovary typically solid, without a locule or an obvious placenta or ovule (containing 1 or 2 embryo sacs- ovules very reduced). Early ontogenetic stages of the ovary sometimes showing a massive central placental column that later fuses with the ovary wall.
Ovule: Apparently absent - without recognizable nucellus or integuments.
Embryo, etc.: monosporic or bisporic. Endosperm development cellular. One few-celled embryo develops in the central tissues of the ovary and is surrounded by endosperm and a layer of sclerenchyma at maturity.

Fruit: A tiny, indehiscent, one-seeded achene. Individual fruits sometimes swollen and aggregated into a flesh multiple fruit.

Seed: Solitary with a very small, undifferentiated embryo embedded in the endosperm.

Chromosomes: X = 8, 9, 12 and more.



Last updated: 14-May-18 / dln