Ranunculaceae: Buttercup Family — Ranunculus (Buttercup)

The buttercup family has a wide variety of plants, but most of them have leaves with 3 lobes, or in groups of 3.

Whitewater Crowfoot – Ranunculus aquatilis var. diffusus

Blooms:

Mar–Sept

Plant Height:

20–80 cm

Flower Size:

Small

Origin:

Native

Habitat:

Marshes, ponds and slow streams

Notes:

This aquatic plant has small 5-petaled white flowers.  It has both floating and submersed leaves, and all are 3–6-dissected into threadlike segments.  Unlike subsp. aquatilis and Lobb’s Aquatic Buttercup (Ranunculus lobbii, see below), its floating leaves are always finely dissected and thread-like.

Common / California Buttercup – Ranunculus californicus var. californicus

Blooms:

Feb–May

Plant Height:

18–70 cm

Flower Size:

Medium

Origin:

Native

Habitat:

Grassland & open woodland

Notes:

A common plant, sometimes found in profusion.  The stem is erect to decumbent, glabrous or spreading-hairy.  There are 5 sepals, and generally 9–17 slender, shiny petals.  Leaves are variable, generally 3-lobed or ternate, with lobes deeply dissected or compound.  Fruits are disk-like, with smooth faces and small, curved, lanceolate beaks.

Downy Buttercup – Ranunculus hebecarpus

Blooms:

Mar–May

Plant Height:

8–25 cm

Flower Size:

Very small

Origin:

Native

Habitat:

Grassland & open woodland

Notes:

A small, inconspicuous plant, difficult to spot until one has learnt how to recognize it. The flowers are tiny, yellowish with 3–5 petals, barely visible among the more prominent (but still tiny) 3 mm-wide disk-like fruits, papillate on their face and with a hooked beak. Basal leaves are in 3s, each leaflet itself being lobed. The cauline leaves are entire and slender.

Lobb’s Aquatic Buttercup – Ranunculus lobbii

Blooms:

Mar–May

Plant Height:

20–80 cm

Flower Size:

Small

Origin:

Native

Rare or endangered?

Yes – 4.2

Habitat:

Vernal pools and shallow ponds

Notes:

This rare aquatic plant has small 5-petaled white flowers, and both floating and submersed leaves.  The floating leaves are deeply 3-parted and occasionally notched.  The submersed leaves are generally 2- or 3-dissected into threadlike segments.  This is distinguished from the more common Whitewater Crowfoot (Ranunculus aquatilis, see above) by having a glabrous receptacle, rather than a bristly one.

Prickle-fruited Buttercup – Ranunculus muricatus

Blooms:

Apr–June

Plant Height:

15–75 cm

Flower Size:

Medium

Origin:

Native

Habitat:

Damp or heavily shaded areas

Notes:

Relatively uncommon.  This is easily distinguished from Common Buttercup (Ranunculus californicus, see above) by having 5 clearly separated petals, and often rounded, deeply-lobed yellowish-green leaves.  Fruits are disk-like, with a long curved beak, and small spines on each face.  These give the plant its common name.