A ligule (from Latin : ligula "strap", variant of lingula, from lingua "tongue") is a thin outgrowth at the junction of leaf and leafstalk of many grasses (family Poaceae) and sedges (family Cyperaceae). A ligule is also a strap-shaped extension of the corolla, such as that of a ray floret in plants in the daisy family Asteraceae. [1]
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The ligule is part of the leaf that is found at the junction of the blade and sheath of the leaf. It may take several forms, but it is commonly some form of translucent membrane or a fringe of hairs. The membranous ligule can be very short 1–2 mm (Kentucky bluegrass, Poa pratensis) to very long 10–20 mm (Johnson grass, Sorghum halepense), it can also be smooth on the edge or very ragged. Some grasses do not have a ligule, for example barnyardgrass ( Echinochloa crus-galli ).
A ligule can also be defined as a membrane-like tissue or row of delicate hairs typically found in grasses at the junction of the leaf sheath and blade. The ligule appears to be a continuation of the leaf sheath and encircles or clasps the stem as does the leaf sheath. The three basic types of ligules are: membranous, a fringe of hairs (ciliate), and absent or lacking. Most grasses have ligules, and the shape, length, and appearance of the ligule margin provide consistent characters for separating genera and some species of grasses.
In grass-like plants such as sedges (Cyperaceae) and rushes (Juncaceae), ligules are usually absent or poorly developed.[ citation needed ]
In members of Asteraceae, a ligule is the elongated tongue of the corolla of a ray flower or ligulate flower. [2]
The microphylls of Lycopodiophyta of the families Selaginellaceae (spikemosses or lesser clubmosses) and Isoetaceae (quillworts) have minute, scale-like flaps of tissue called ligules at the base of the upper surface of each leaf blade. This feature distinguishes them from clubmosses of the family Lycopodiaceae. [3] : 7
The family Asteraceae, with the original name Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae were first described in the year 1740. The number of species in Asteraceae is rivaled only by the Orchidaceae, and which is the larger family is unclear as the quantity of extant species in each family is unknown.
Salvia funerea, is a species of semi-deciduous perennial shrub with the common names Death Valley sage, woolly sage, and funeral sage, is an intricately branched shrub associated with limestone soils in the Mojave Desert in California and Nevada. It is characterized by an overall white appearance due to wooly hairs that cover the stems and leaves.
Carex is a vast genus of nearly 2,000 species of grass-like plants in the family Cyperaceae, commonly known as sedges. Other members of the family Cyperaceae are also called sedges, however those of genus Carex may be called true sedges, and it is the most species-rich genus in the family. The study of Carex is known as caricology.
Layia platyglossa, commonly called coastal tidytips, is an annual wildflower of the family Asteraceae, native to western North America.
Sorghastrum nutans, commonly known as either Indiangrass, yellow Indiangrass, or golden feather grass, is a North American prairie grass found in the Central United States, the Eastern United States, and Canada, especially in the Great Plains and tallgrass prairies.
Symphyotrichum is a genus of over 100 species and naturally occurring hybrids of herbaceous annual and perennial plants in the composite family, Asteraceae, most which were formerly treated within the genus Aster. The majority are endemic to North America, but several also occur in the West Indies, Central and South America, as well as one species in eastern Eurasia. Several species have been introduced to Europe as garden specimens, most notably New England aster and New York aster.
This page provides a glossary of plant morphology. Botanists and other biologists who study plant morphology use a number of different terms to classify and identify plant organs and parts that can be observed using no more than a handheld magnifying lens. This page provides help in understanding the numerous other pages describing plants by their various taxa. The accompanying page—Plant morphology—provides an overview of the science of the external form of plants. There is also an alphabetical list: Glossary of botanical terms. In contrast, this page deals with botanical terms in a systematic manner, with some illustrations, and organized by plant anatomy and function in plant physiology.
Rhynchospora alba, the white beak-sedge, is a plant in the sedge family, Cyperaceae. It is a tufted herbaceous perennial around 50 cm tall, with white inflorescences that flower in August. The fruit of the sedge is a small achene with a characteristic beak-like cap. It is dispersed by wind or falls by gravity, leading to individuals existing in tight clumps. The species favours wet, acidic and nutrient poor soils, thriving in Sphagnum-dominated bogs, but also peaty grasslands. As such, it is often used as a positive indicator for bog and mire ecosystem health.
This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary of leaf morphology. For other related terms, see Glossary of phytopathology, Glossary of lichen terms, and List of Latin and Greek words commonly used in systematic names.
Malacothrix glabrata, commonly known as the smooth desert dandelion or desert dandelion, is an annual plant in the family Asteraceae. It is common to the southwestern deserts of North America and has showy pale-yellow to white flowers. The name "glabrata" refers to the leaves being (nearly) hairless. Like other members of its genus, it has a milky sap and flower heads composed of smaller strap-like flowers called "ligules".
Syntrichopappus is a genus of flowering plants in the family Asteraceae, found in the Southwestern United States and northern Mexico, including Baja California. It is a member of the Heliantheae alliance of the Asteraceae. There are two species. Common names include xerasid and Frémont's-gold.
Melica ciliata, the hairy melic or silky spike melic, is a species of flowering plant in the grass family Poaceae, native to Europe, north Africa and temperate Asia. It has been introduced to South Australia.
Festuca vivipara, the viviparous sheep's-fescue, is a species of grass native to northern Europe, northern Asia, and subarctic North America. The specific epithet vivipara is Latin, referring to the florets' alteration to leafy tufts. The plant can have a diploid number of 28, 49, 56, or 63, though numbers of 21, 35, and 42 have also been reported.
Melica rigida is a species of grass found in Argentina, Brazil, and Uruguay.
Agrostis thurberiana is a species of grass that is native to northwest and southwest United States and Canada.
Festuca actae is a species of grass which can be found in New Zealand.
Syntrichopappus fremontii, is a small annual plant in the family(Asteraceae. It has yellow flower heads and grows in the Mojave Desert, to Utah and northwestern Arizona.
Carex rosea, the rosy sedge, is a flowering plant and part of the family Cyperaceae. Synonyms for Carex rosea include Carex concoluta, and Carex flaccidula. It is native to central and eastern North America and it exists in wet to dry soils. Carex rosea can be found in shores of streams and bottomlands, as well as ponds. It is known to have good adaptations to dry-shade locations. It is an evergreen plant which is easy to grow.
Rytidosperma bipartitum, the leafy wallaby grass, is a perennial species of grass found in south eastern Australia. Usually found on the heavier clay or on loamy soils in open eucalyptus woodland. The habit is somewhat variable, erect and densely tufted. The grass may grow up to 0.7 m tall.
Carex vestita, also commonly known as velvet sedge, is a tussock-forming species of perennial sedge in the family Cyperaceae. It is native to eastern parts of the United States.