Soft bird’s beak (Chloropyron molle ssp. molle) is a rare annual plant with an interesting life cycle, and it is native to the East Bay. While some species in the Chloropyron genus occur in California, Nevada, Oregon, Utah, and Baja California in Mexico, Chloropyron molle ssp. molle is only found in California and only in coastal and inland salt marshes in Contra Costa, Sonoma, Marin, Napa, and Solano counties (see its Calflora distribution map). It’s one of many rare plants whose populations botanists are tracking through Calflora.
In addition to tolerating high levels of salt in its marsh habitat, soft bird’s beak is unusual as a hemiparasitic plant that gets part of its nutritional needs from host plants, including salt grass (Distichlis spicata) and pickleweed (Salicornia spp.). Fully parasitic plants develop a haustorium, an organ that connects to the host plant’s vascular system. Hemiparasitic plants are able to photosynthesize to some degree, but they also develop a haustorium to obtain nutrition from other plants.
Many of us remember when soft bird’s beak was in the genus Cordylanthus. The genus name Cordylanthus is derived from the Greek words for “club flower,” and it was originally published by George g Bentham in 1846 (based on work by Thomas Nuttall). There are currently two East Bay subspecies that are still categorized in the genus Cordylanthus:
Cordylanthus pilosus ssp. pilosus (hairy bird’s beak)
Cordylanthus rigidus ssp. rigidus (rigid bird’s beak)
According to Michael Charters’ California plant names website, Calflora.net (not to be confused with Calflora.org!), the genus name Chloropyron comes from chloros, meaning “green” or “greenish-yellow,” and the roots pyr- or pyros, possibly meaning “divine,” ” fire,” or “grain.” The genus Chloropyron was published by Hans Hermann Behr in 1805.
While parts of both genus names describe aspects of soft bird’s beak—its tubular flowers are yellowish and club-shaped–it was the plant’s genetics that led to the name change. David Tank, Mark Egger, and Richard G. Olmstead’s molecular phylogenetic work led to the reclassification and genus name change to Chloropyron for some species and subspecies in the genus Cordylanthus, including soft bird’s beak. In their 2009 paper, “Phylogenetic classification of subtribe Castillejinae (Orobanchaceae),” the researchers wrote, “We resurrect the generic name Chloropyron for the halophytes previously recognized as [Cordylanthus subgenus] Hemistegia.”
Soft bird’s beak has not been doing well in its East Bay habitat of late. The East Bay Regional Park District (EBRPD) has been using Calflora to track changes in this plant’s populations over time. This year, a group from Calflora, EBRPD, and CNPS East Bay Chapter conducted soft bird’s beak surveys at Point Pinole Regional Shoreline. Population sizes at Point Pinole in 2022 are one-third to one-tenth of what they were in 2020. EBRPD’s rare plant botanist Michele Hammond says, “This year, plant counts for Chloropyron molle ssp. molle populations have been lower than in past years, perhaps related to extreme drought and/or heat conditions.”
You can follow soft bird’s beak in Calflora as the East Bay Regional Park District continues to monitor its populations. Calflora, EBRPD, and CNPS East Bay look forward to more outings together to track these (and other) incredible plants in our region. If you’d like to participate in future Calflora plant walks in the East Bay or elsewhere please sign up here.
— Cynthia Powell, Executive Director, Calflora