Glossary: L
- labellum
- In orchids, the lowest, highly modified petal.
- lacerate
- With a jagged margin that appears torn.
- laciniate
- Cut into narrow lobes or long teeth.
- lacuna
- A space or gap within a tissue.
- laminar
- Thin, with broad faces (as with a leaf).
- lanceolate
- Widest below the middle and tapering at both ends, narrower than ovate but wider than linear; lance-shaped.
- lanceoloid
- The 3-dimensional equivalent of lanceolate: widest below the middle and tapering at both ends, lance-shaped.
- lateral
- On or to the side.
- lateral vein
- A vessel that branches off the main midvein of a leaf.
- latex
- A clear or colored (often milky) liquid produced by plants.
- latitudinal
- Perpendicular to the main axis.
- lax
- Loose, open; drooping.
- leaf
- A flattened, lateral appendage of the axis of a plant that conducts photosynthesis.
- leaflet
- One of the expanded, first-order-division portions of a compound leaf.
- leafule
- The ultimate segment of a twice-compound leaf (the division of a leaflet).
- legume
- The fruit pod characteristic to species of the Fabaceae (the species are also referred to as "legumes").
- lemma
- In grasses (Poaceae), the outer of the two bracts enclosing a floret.
- lenticel
- A small, corky dot or streak on the bark or roots of woody plants, normally arising around pores.
- lenticular
- Lens-shaped; in cross-section with two convex surfaces.
- lepidote
- Covered with small scales.
- leptosporangiate
- With a sporangium one cell layer thick, and an annulus and stalk (compare eusporangiate).
- liana
- A woody, climbing or trailing plant that does not support its own weight.
- ligule
- A projection or collar on the leaf sheath of grasses (Poaceae), Cyperaceae, or a small triangle of tissue on the fertile leaves of quillworts (Isoetes species) or Selaginella.
- ligules
- Plural of ligule.
- limb
- The expanded portion of a tubular corolla, in front of the throat.
- linear
- Very narrow, with more or less parallel sides, narrower than lanceolate.
- lip
- A projecting portion of a corolla or calyx whose petals or sepals are fused into a tube.
- lobe
- A projection from an edge of a plant structure (such as a leaf), larger than a tooth.
- locule
- Chamber containing seeds in an ovary.
- loment
- A schizocarp of some plants in the Fabaceae composed of one-seeded parts that separate from each other.
- lycophyte
- The group broadly containing the Lycopodiaceae, Selaginellaceae, Huperziaceae, and Isoetaceae - spore-bearing plants usually with tiny leaves (compare with monilophyte).