''Horkelia tenuiloba'' is a species of flowering plant in the rose family known by the common names Santa Rosa horkelia and thin-lobed horkelia. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

, where it is known only from the coastal hills and mountains north of the

San Francisco Bay Area The San Francisco Bay Area, often referred to as simply the Bay Area, is a populous region surrounding the San Francisco, San Pablo, and Suisun Bay estuaries in Northern California. The Bay Area is defined by the Association of Bay Area Go ...

. It is a plant of

chaparral Chaparral ( ) is a shrubland plant community and geographical feature found primarily in the U.S. state of California, in southern Oregon, and in the northern portion of the Baja California Peninsula in Mexico. It is shaped by a Mediterranean c ...

habitat. This is a perennial herb producing a low mat of hairy, glandular green foliage around a woody base. The leaves are cylindrical or somewhat flat, often tapering to a point, and each is made up of several densely packed pairs of hairy leaflets. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

is an array of flowers atop an erect stalk, each flower made up of five pointed green

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...

s and five white petals. At the center of the flower is a cone of

stamen The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filame ...

s tipped with reddish anthers around many

pistils Gynoecium (; ) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) ''pistils'' ...

. It flowers in May Horkelia tenuiloba
iNaturalist It is threatened by trampling, trail maintenance, and development.

References

External links

Jepson Manual TreatmentPhoto gallery
tenuiloba Flora of California {{rosoideae-stub