Plants ranked as California Rare Plant Rank 4 are on the watch list: plants of limited distribution. There are 31 taxa in the East Bay of rare plant rank 4.
Acanthomintha lanceolata (Santa Clara thornmint)Androsace elongata ssp. acuta (California androsace)
Arabis blepharophylla (coast rock cress)
Aspidotis carlotta-halliae (lace fern)
Atriplex coronata var. coronata (crownscale)
Calandrinia breweri (Brewer's calandrinia)
Calochortus umbellatus (Oakland star tulip)
Castilleja ambigua ssp. ambigua (johnny-nip)
Clarkia breweri (Brewer's clarkia)
Clarkia concinna ssp. automixa (Santa Clara red ribbons)
Collomia diversifolia (serpentine collomia)
Convolvulus simulans (small-flowered morning-glory)
Eleocharis parvula (small spikerush)
Eriogonum umbellatum var. bahiiforme (bay buckwheat)
Eriophyllum jepsonii (Jepson's woolly sunflower)
Erythranthe laciniata (cut-leaved monkeyflower)
Fritillaria agrestis (stinkbells)
Galium andrewsii ssp. gatense (phlox-leaf serpentine bedstraw)
Hesperevax caulescens (hogwallow starfish)
Iris longipetala (coast iris)
Juglans californica (Southern California black walnut)
Lasthenia ferrisiae (Ferris' goldfields)
Leptosiphon ambiguus (serpentine leptosiphon)
Leptosiphon aureus (bristly leptosiphon)
Leptosiphon grandiflorus (large-flowered leptosiphon)
Lessingia tenuis (spring lessingia)
Lilium rubescens (redwood lily)
Microseris sylvatica (sylvan microseris)
Navarretia heterandra (Tehama navarretia)
Piperia michaelii (Michael's rein orchid)
Ranunculus lobbii (Lobb's aquatic buttercup)
