Glossary: B
- bark
- The outermost layer of non-living tissue on the main stem of a woody plant.
- basal
- At the bottom or base of; "all basal" leaves are confined to the base of the plant (compare alternate, whorled, or opposite leaves).
- base
- Bottom of a plant at the ground, or proximal part of structure where it meets another structure (i.e., leaf base near junction with petiole).
- basifixed
- Attached at the base, as in the area where a petiole meets the leaf blade.
- basipetal
- In the direction of the base.
- basiscopic
- In the direction of the basal end.
- beak
- Slender projection.
- beard
- Tuft of long hairs.
- berry
- A fleshy fruit with a juicy or succulent wall (called a pericarp) that encloses two or more seeds.
- biennial
- A plant that lives for two years, usually reproducing only in the second year before dying.
- bifid
- Divided at the tip into two equal parts by a cleft (think "Pac Man").
- bilabiate
- A corolla with two prominent lips and petals that are fused (usually into a tube) at the base.
- bipinnate
- Twice-divided, as with leaves that are further subdivided into separate leaflets.
- bisexual
- A flower that bears both pollen-bearing organs (stamens) and ovule-bearing organs (carpels); aka "perfect".
- bladder
- A hollow appendage that assists with flotation or captures prey (in Utricularia species).
- blade
- The expanded, outer portion of an organ, such as a leaf or petal, as opposed to the narrow, basal or inner portion.
- bloom
- A white or white-blue powdery or waxy coating on a surface that can be rubbed away; or, a term referring generally to the flower.
- blunt
- Ending abruptly in a rounded or squared-off tip; opposite: "sharp".
- bract
- A modified leaf that subtends an inflorescence or flower that is not part of the flower proper, commonly of reduced size compared with the foliage leaves.
- bracteate
- Having bracts.
- bracteole
- A small, modified leaf that grows just beneath the flower or on the pedicel above larger bracts.
- branch
- The side shoot of a stem or flower stem.
- branched hairs
- Hairs with divided tips.
- branchlet
- An ultimate segment of a branch; a twig.
- bristle
- A stiff hair.
- brittle
- Easily broken when bent, as in some branchlets of Salix (willow) species.
- broad leaf
- Leaves with blades that are conspicuously flattened and wider than needles.
- bud
- An undeveloped leafy shoot or flower.
- bulb
- Underground storage organ enclosed by leaf bases or fleshy scales, such as an onion.
- bulbiferous
- Having bulbs.
- bulbil
- A small, leafy bulb, usually produced in the axils, capable of growing into a new plant; it is a plantlet that is genetically identical to the parent.
- bulblet
- A small bulb, usually arising from a parent bulb.
- bulbous
- Swollen.
- bundle scar
- A mark on the stem of a woody plant, created by the petiole and vascular bundles of vessels, that shows where a fallen leaf or twig had been attached; aka "leaf trace".
- bundle sheath
- Cylinder of cells surrounding a vascular bundle or bundle scar.
- bush
- Shrub.
- buttress
- Flares or extension of a tree base that support the main stem.