Petalidium, commonly known as petal-bushes, is a genus of perennial shrubs in the acanthus family.[1] They are native to sandy flats or stony slopes in the drier bush regions of Africa, India and the Mascarene Islands.[2] The majority of species occur in frost-free, summer rainfall regions of southern Africa,[3] and may be found from low to medium altitudes.
They have a diverse habit, forming either small, scrambling herbs or large, robust shrubs.[3] Their dilated, tubular flowers are solitary or on short racemes growing from the leaf axils, and vary from white to mauve or red in colour. The four stamens are partially fused with the corolla, and the style is branched into two unequal parts. The calyx is deeply divided into five segments.[2]
Two large, ovate to elliptic bracteoles subtend and protect the young corolla.[2] The persistent bracteoles may be conspicuously veined or covered by long, villous trichomes. The small, ellipsoid fruit capsules explosively release two to four flat seeds (two ovules per ovary cell) when moisture is absorbed by their hygroscopic hairs.[1] Young foliage and branches are covered in gland-tipped hairs. The leaves are entire.[2]
Some species are cultivated as ornamentals, as they grow fast and flower profusely.
According to Jackson (1990),[4] the name Petalidium is derived from the Greek petalon (a leaf or petal), which may refer to the deciduous, leaf-like bracts, while bracteatum likewise refers to the large, imbricate (i.e. overlapping) bracts.[1]
There are more than 30 species in all,[5] of which 29 occur in southern Africa.[6] The species include:
Petalidium, commonly known as petal-bushes, is a genus of perennial shrubs in the acanthus family. They are native to sandy flats or stony slopes in the drier bush regions of Africa, India and the Mascarene Islands. The majority of species occur in frost-free, summer rainfall regions of southern Africa, and may be found from low to medium altitudes.
Petalidium es un género de plantas con flores perteneciente a la familia Acanthaceae. El género tiene 52 especies[1] de hierbas descritas y de estas, solo 16 aceptadas. Son naturales de las zonas tropicales de África, Madagascar e Himalaya.[2]
Son arbustos bajos peludos con hojas ovaladas o estrechamente oblongas, enteras o dentadas. Flores sésiles o subsessiles, solitarias, en las ramas laterales, de color blanco o azul. Corola, arriba recta o curva de tubo dilatado o infundibuliforme. Cápsula comprimida, ± estipitada. Semillas discoides, cubiertas con pelo higroscópico.[3]
El género fue descrito por Christian Gottfried Daniel Nees von Esenbeck y publicado en Plantae Asiaticae Rariores 3: 75, 82. 1832.[3] La especie tipo es: Petalidium barlerioides
Petalidium es un género de plantas con flores perteneciente a la familia Acanthaceae. El género tiene 52 especies de hierbas descritas y de estas, solo 16 aceptadas. Son naturales de las zonas tropicales de África, Madagascar e Himalaya.
Petalidium est un genre de plantes de la famille des Acanthaceae.
Selon Catalogue of Life (12 août 2017)[2] :
Selon NCBI (12 août 2017)[3] :
Selon The Plant List (12 août 2017)[4] :
Selon Paleobiology Database (12 août 2017)[5] :
Selon Tropicos (12 août 2017)[1] (Attention liste brute contenant possiblement des synonymes) :
Selon World Register of Marine Species (12 août 2017)[6] :
Petalidium est un genre de plantes de la famille des Acanthaceae.
Petalidium là chi thực vật có hoa trong họ Acanthaceae.[1]
Petalidium là chi thực vật có hoa trong họ Acanthaceae.
