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 (not shown) 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:
This is a small, inconspicuous plant, difficult to spot until one has learned to recognize it. The tiny flowers have 3-5 yellowish petals. They are barely visible among the more prominent 3 mm-wide disk-like fruits. The fruits are papillate on their face, with a hooked beak. Basal leaves are in 3s, each leaflet 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. Photo #3 by CJH.
