Dudleya parva

This species of Dudleya is an especially unique taxa, as it possesses several characteristics intermediate within the genus. It was previously thought Dudleya were organized into three subgenera; Dudleya, Stylophyllum, and Hasseanthus. It was thought that Dudleya and Hasseanthus were the most distant from each other, and that Stylophyllum occupied an intermediate space. Dudleya were thought to have evergreen leaves and habit, while Hasseanthus were classified with a deciduous, geophytic habit. Dudleya parva, however, was originally classified in the subgenera Dudleya, but it presents several traits of Hasseanthus. It has summer deciduous leaves, and a rhizomatous habit. It is also unusual among Dudleya in that it may be rooted from the leaves, which has only been recorded among other Hasseanthus-type Dudleya.[6]

Arising from stems may be multiple rosettes, at most several, each 1 to 6 cm wide. The roots are narrowed and swollen at irregular intervals, with rhizome-like branches extending from the roots of the plant. The rhizomes often resemble shriveled roots for most of the year, and are very fragile. The rhizomes are not a good character for field identification. Because the plant is rhizomatous, the above-ground parts of the plant may die back for several years, surviving underground as a rootstock. It is a long-lived species, with some examples surviving over 24 years in cultivation.[6][7]

The stems are 2 to 7 mm wide. The leaves are deciduous in summer, and are 1.5 to 4 cm long, 3 to 6 mm wide, and shaped oblanceolate, glaucous in youth, but papery when dry. The base of the leaves is a wounding purple to red. The peduncle of the inflorescence is 4 to 23 cm tall, and 1 to 5 mm wide. The lower bracts are 5 to 15 mm, and the inflorescence branches once or twice. The petals are yellow, and the keel is often flecked with red.[7]

The 2n chromosome number is 34.[7]

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  A budding specimen
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  Budding flower stalks arising from the base
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  The basal rosettes