bog orchids

genus Platanthera

Member of orchidoid orchids (subfamily Orchidoideae)
orchid family (family Orchidaceae)
monocots (class Liliopsida)
flowering plants (subphylum Angiospermae)

Except for historical records that I'm ignoring, there are no other wild species of this genus in the bay area.

All California species have a spur sticking out behind the lower petal which is key to identification. This spur may be difficult to spot since it is likely to be greenish and snuggled up against the flower stalk.

Key features:

leaves parallel to stem and folded lengthwise or ascending and not folded
perianth color
sepals spreading or reflexed
spur length, held horizontally or curved along the stalk.

CalFlora and Jepson have this species correctly in Platanthera.

sierra bog orchid
Platanthera dilatata var. leucostachys

2 leaves, alternate, along stem, with 1 lengthwise fold
perianth white to cream

CalFlora and Jepson have these species in their old genus, Piperia.

These flowers have 2–5 ± basal leaves which Jepson does not describe in detail. Possibly they are ascending, but not completely parallel to the stem nor folded lengthwise.