Amborella trichopoda is a rare, understory shrub or small tree. The
leaves are alternately arranged, evergreen, and simple, with slightly
serrated margins. Amborella exhibits a number of noteworthy
morphological features. For example, Amborella does not posses vessel
elements for water conduction as do virtually all other flowering plants.
The plant is dioecious (with separate male and female plants) and has
small flowers with spirally arranged parts. The flowers possess an
undifferentiated perianth of tepals (petal-like organs). For male flowers
there are 9-11 tepals, and 11-22 stamens (which carry pollen); for
female flowers, 5-8 tepals, zero to several staminodes (sterile stamens),
and four to six carpels (which eventually become fruits). There is a
developmental transition between leaf-like bracts and perianth, perianth
and stamens, and between stamens and carpels. The stamens are
laminar (leaf-like) and the carpels are sealed by a secretion of sticky
fluid, rather than developmentally fused as in most angiosperms. The
fruit is a red berry containing a single seed. The chromosome number is
2n = 26.
Description