Dictionary

Word	Meaning
Abaxial	The side of an organ away from the axis on which it is inserted, such as the lower surface of a leaf. Abaxial is the opposite to adaxial.
Accrescent	Continuing to grow after flowering.
Achene	A one-seeded dry fruit with no wings, and with its seed having one point of attachment only.
Actinomorphic	Radially symmetric flowers that can be divided into mirror-image halves by a straight line passing in any direction through the mid-point. The flower is radially symmetrical because the petals and sepals are of similar size and shape. In contrast, a flower that is zygomorphic has bilateral symmetry. Most flowers are actinomorphic.
Acuminate	Drawn out into a long, tapering point with the terminal angle less than 45 degrees. Same meaning as attenuate.
Acute	Referring to a leaf shape, the terminal angle 45 degrees to 60 degrees, and with a sharp point.
Adaxial	The side of an organ towards the axis on which it is inserted, such as a leaf's upper surface. Abaxial is the opposite to adaxial.
Adnate	Attached surface to surface, usually referring to different organs or structures, such as stamens and petals. See connate.
Adpressed	Lying close together, but not fused, and pointing toward the apex of the plant or stem. Usually refers to leaves growing up against the stem. See appressed.
Adventitious	A term referring to roots or shoots that arise from unexpected or unusual positions.
Aerial roots	Roots produced by a tree above ground that find their way to water and nutrients.
Alluvial	Sand or clay soils that have been deposited by a river.
Alternate	Referring to leaf layout, leaves growing from alternating sides of each successive node.
Alternipetalous	Alternating with the petals, such as petal, stamen, petal, stamen.
Ament	An ament is an elongated and hanging spike or cluster of flowers, which are usually unisexual, sessile or sub-sessile, and without petals. Aments typically fall as a unit once fruiting is complete. The preferred term is catkin.
Amplexicaul	The stipules or the base of the leaf stalk wrap around the stem to the opposite side.
Androgynophore	A stalk that lifts both the male and female flowering parts further above the perianth. Andro- refers to male and gyno- refers to female.
Androgynous	Partly male and partly female in appearance; of indeterminate sex.
Angiosperms	Flowering plants. The seeds of angiosperms are enclosed in an ovary, which develops into a fruit after germination. This is unlike the seeds of gymnosperms that are 'naked' during pollination. More than 80% of all plant species are angiosperms. Angiosperms divide into two primary groups called monocotyledons or monocots, and dicotyledons or dicots.
Angustate	Narrowing. The species name for Boscia angustifolia derives from the term angustate, which is derived from the Latin word for narrowed.
Anther	The part of a stamen at the tip of the filament that produces and stores pollen. An anther consists of two lobes, each having a pair of pollen sacs called microsporangia, that produce pollen. The filament and anther together constitute the stamen. See pistil.
Antherode	The remnant of an anther
Apetulous	A flower without any petals.
Apex	The tip of a leaf or fruit, or other organ.
Apical	Of the apex. An apical bud, or meristem, is the growing tip at the apex of a stem. The preferred term is distal, being the furthest point from the place of attachment.
Apical dominance	Growth of the apical bud that inhibits growth of axillary buds.
Apical meristem	A region of undifferentiated plant tissue that is capable of active division, at the tip or apex of a growing stem or root.
Apiculate	Referring to the apex of a leaf ending in an abrupt, short, sharp point, usually slightly twisted, as in Combretum apiculatum. Refer to mucronate.
Apocarpous	Having distinct carpels, not joined together. See syncarpous.
Appressed	Lying close together, but not fused, and pointing toward the apex of the plant or stem. The term usually refers to leaves growing up against the stem.