Parasitic Genera Included: Only one genus, Krameria L.
Habit: Perennial herbs and shrubs.
Parasitism: Hemiparasites. See Musselman (1976, Phytomorphology 25:416).
Roots: Large, fleshy storage roots. Medicinal extract from the dried roots of "rhatany root" (Bolivia and Peru) has astringent properties and was used as a tooth preservative. The root of K. tomentosa contains tannins useful for tanning and K. parvifolia (W. U.S. and Mexico) was extracted for its dye used to color wool and was used by Papago Indians to treat sore eyes.
Stem: Thin rhizomes as well as aerial stems. Often covered with short, soft or silky hairs. Cork cambium present; initially deep-seated. Internal phloem absent. Secondary thickening developing from a conventional cambial ring. 'Included' phloem absent. Vessel end-walls simple. Wood parenchyma scanty paratracheal.
Leaves: Alternate, simple (or unifoliolate since some are rarely trifoliolate?) or ternate, entire, estipulate. The mesophyll with sclerencymatous idioblasts, calcium oxalate crystals (druses).
Inflorescence: Solitary and axillary or in terminal racemes.
Plant Sex: Plants hermaphrodite.
Flowers: Subtended by two leaflike bracteoles, perfect, hypogynous, strongly irregular.
Calyx: Of 5 (rarely 4) unequal, petaloid, distinct, imbricate sepals; the 3 outer ones larger than the two inner ones, nearly enclosing the flower, or seldom all the sepals reflexed.
Corolla: Of 5 (rarely 4) petals; the upper three long-clawed, distinct or connate by their claws, the two lower ones smaller, broad, thick, sessile, often modified into lipid-secreting glands.
Nectary: Disk absent.
Androecium: Of 4 (rarely 3 or 5) stamens, alternating with the upper petals; a fifth sterile stamen (staminode) rarely found on the anterior side of the flower; filaments thick, distinct or connate at base, or adnate below to the claws of the upper petals; anthers tetrasporangiate and dithecal, opening by two terminal pores; pollen 3 (4)-colporate, varying to triporate, with horizontal, elongate pores.
Gynoecium: Superior, bicarpellate, one carpel fully-developed and the other vestigial and empty; style obliquely terminal with a discoid or punctiform stigma.
Ovule: Two in the single, fertile locule, colateral, pendulous, epitropous, anatropous, bitegmic.
Embryo, etc. Embryo well differentiated, straight, with two, thick cotyledons. One ovule per fruit develops, the other aborts.
Fruit: A dry, indehiscent, thick-walled, globose, 1-seeded "achene" covered with bristles or spines, often retrorsely barbed.
Seed: With a straight embryo and two thick, starchy cotyledons; endosperm lacking. Early seedling development may be autotrophic (Musselman and Mann 1977, Sida 7:224).
Chromosomes: X = 6.
Link to Family Description in Delta
SIUC / College of Science /
Parasitic Plant Connection / Krameriaceae
Last updated: 17-Jun-10 / dln