Ehrendorferia is a small genus of two species of biennial or perennial herbaceous plants in the family Papaveraceae (subfamily Fumarioideae, tribe Ehrendorferieae), commonly known as eardrops. Both species are native to California and the Baja California peninsula of Mexico, where they grow in dry, brushy habitats prone to wildfire — making them classic fire-following plants whose seeds germinate in response to fire or smoke.
The genus was established in 1997 by Fukuhara and Lidén as a nomen novum, separating this lineage from Dicentra s.l. on the basis of molecular phylogenetic evidence (plastid gene rps16 intron). It was named in honor of the Austrian botanist Friedrich Ehrendorfer on the occasion of his 70th birthday. The homotypic synonym Dicentra subgen. Chrysocapnos Engelm. (1881) predates the current name.
Plants are tall for members of Fumarioideae — Ehrendorferia ochroleuca holds the record for the subfamily, reaching up to 4 m. Leaves are blue-green and glaucous, pinnately divided. Flowers are characteristic of the fumitory alliance: four petals in two pairs, the outer pair pouched at the base and curved outward at the tip, the inner pair connected at the tip. Ehrendorferia chrysantha bears yellow, aromatic flowers in panicles on branched stems to 1.5 m; Ehrendorferia ochroleuca bears dull white flowers with purple tips in round clusters, and is visited by hummingbirds for nectar.
Seeds are enclosed in capsules and exhibit smoke- or fire-stimulated germination, an adaptation to the chaparral and coastal sage scrub fire cycles of their native range.
Etymology
The genus name Ehrendorferia honors the Austrian botanist Friedrich Ehrendorfer; it was coined by Fukuhara and Lidén in 1997 as a nomen novum when molecular phylogenetics supported the separation of this clade from Dicentra s.l. The common name "eardrops" refers to the pendant, ear-shaped flowers typical of the fumitory family.
Distribution
Both species are native to California and the Baja California peninsula of Mexico. Ehrendorferia chrysantha occurs in dry, brushy wildfire-prone areas across California; Ehrendorferia ochroleuca is restricted to gravelly chaparral and woodland habitats of the Peninsular, Transverse, and southern Coast Ranges of California and adjacent Baja California.
Ecology
Ehrendorferia species are fire-followers (pyrophytes). Seeds of both species require exposure to fire or smoke to break dormancy — a germination strategy adapted to the chaparral fire cycle of their native range. Ehrendorferia ochroleuca is also pollinated by hummingbirds, which visit the flowers for nectar.
Taxonomy Notes
Ehrendorferia was segregated from Dicentra s.l. in 1997 by Fukuhara and Lidén based on phylogenetic analysis of the plastid rps16 intron (Lidén et al., Plant Systematics and Evolution 206: 411–420). The genus is placed in subfamily Fumarioideae, tribe Ehrendorferieae, within Papaveraceae. The homotypic synonym is Dicentra subgen. Chrysocapnos Engelm. (1881). Both species were previously treated as Dicentra chrysantha and Dicentra ochroleuca respectively.
