| Involucre |
A ring or whorl of small leaves, or bracts, at the base of a flower, flower cluster, or fruit. In Euphorbiaceae the involucre is the cuplike structure that holds the nectar glands, nectar, and head of flowers, and sits above the bract-like cyathophyll structure. |
| Involute |
Relating to a leaf, the margins rolled upwards, towards the adaxial, or upper leaf surface. See revolute. |
| Jugate |
Describes a structure of paired items joined together, such as opposite leaflets on a rachis. The word comes from the Latin, jugatus, meaning joined. |
| Lamina |
Leaf blade. |
| Lanceolate |
Narrowly lance-shaped, and being widest about one third from base and pointed at both ends. Oblanceolate, is widest about two-thirds up from the base. |
| Lateral vein |
Secondary vein, or the first level of branching off the midrib. |
| Latex |
A fluid that is released from a damaged point of a plant. Latex may be milky-white, as in Euphorbia or Ficus species. |
| Lax |
Loose from one another, and possibly drooping. |
| Leaf |
A leaf is a plant's principal organ of photosynthesis, and it is an outgrowth of the stem. |
| Leaf axil |
The upper angle between a leaf and its supporting stem. |
| Leaflet |
One portion or part of the blade of a compound leaf. |
| Legume |
A dry fruit, that is a pod, formed from one carpel, and is either dehiscent along both sides, or indehiscent. Legumes are characteristic of the Fabaceae, Mimosaceae and Caesalpiniaceae families. |
| Lenticel |
A pore in the outer layer of a woody stem through which an interchange of gases takes place. The plant loses water through its lenticels. |
| Lenticellate |
With lenticels. Refer to lenticel. |
| Lepidote |
With small scales across the surface. |
| Liana |
A climbing plant, such as forest vines, with long woody stems that use other plants to gain height while rooted in the ground. See scandent. |
| Liane |
A climbing plant, such as forest vines, with long woody stems that use other plants to gain height while rooted in the ground. The alternative term is liana. See scandent. |
| Lignin |
Lignin is a plant substance that is durable and tough, and forms into vital structural materials to support plant tissues. Lignins are deposited in cell walls, providing rigidity, particularly in wood and bark. |
| Linear |
When referring to a leaf share, very narrow, with length more than 5 times the width, and the sides parallel. |
| Lithophyte |
A plant with germinates and grows on rocks. Several fig species are lithophytes, with their roots then locating and rooting in soil. |
| Lithophytic |
A plant with germinates and grows on rocks. Several fig species are lithophytes, with their roots then locating and rooting in soil. |
| Lobe |
A corolla tube that is continuous at the base may open into petal-like segments, called lobes. |
| Lobed |
When referring to a leaf share, with several points and deeply indented margins. |
| Locule |
A cavity in the carpel that houses the ovule or ovules. |
| Loment |
Pods flattened between each seed, and splitting along the flattened sections into individual sections between the seeds. |
| Lomentum |
Pods flattened between each seed, and splitting along the flattened sections into individual sections between the seeds. |
| Margin |
The outer edge of the leaf. |
| Mealy |
Covered with particles that resemble flour. |
| Membrane |
A membrane is a thin, flexible, film-like structure that separates the interior of the cell from the outside environment. Cell membranes are semipermeable and often translucent. They regulate the transfer of materials into and out of the cell. |
| Mericarp |
An individual, single seeded carpel of a schizocarp. It is a segment of a fruit that splits away as a perfect fruit itself. |
