Asteraceae – Dandelion 22017-08-16T11:27:12+00:00

 Asteraceae: Sunflower Family – Cichorieae (Dandelion) Tribe: Various non-natives

The Sunflower family is a very large family with over 25,000 members.  Botanists subdivide the family into a number of tribes of which 14 are represented in Monterey County, one of these, the Heliantheae or Sunflower tribe, being further broken down into subtribes of which 9 are represented in Monterey  County. The Cichorieae (Dandelion) tribe has two distinctive features.  The first is that they all have stems with milky sap.  The second (and more important) is that they do not have disk and ray flowers like typical daisies.  Instead they have what are called “ligules” which resemble strap-like ray flowers but, unlike ray flowers, have both male and female parts – without which no reproduction would be possible.  Another difference is that ray flowers have 0–3 lobes at the tip; ligules have 5. This page covers a number of non-native plants, most of them weedy and some invasive.

Smooth Cat’s Ear – Hypochaeris glabra

Blooms:

Apr–Aug

Plant Height:

10–40 cm

Flower Size:

Small

Origin:

Europe

Invasive?

Yes – limited

Habitat:

Grassland

Notes:

Very common in grassland, often in large numbers. Most easily distinguished by the small size of its flower heads (no more than 1 cm across) and the hairless leaves in a basal rosette.  Buds are long and slender with purple-tipped phyllaries. Fruits are of 2 different types in a single head.  The outer fruits are cylindric, tapered to the base only and with no beak.  Inner fruits are tapered at both ends and have long beaks. The pappus of both is noticeably plumose.

Hairy Cat’s Ear – Hypochaeris radicata

Blooms:

Apr–Nov

Plant Height:

40–75 cm

Flower Size:

Medium

Origin:

Europe

Invasive?

Yes – moderate

Habitat:

Grassland, open woodland, disturbed areas

Notes:

Easily distinguished from the Smooth Cat’s Ear (Hypochaeris glabra) by its larger flowers (typically about 2 cm across), its coarser, hairy leaves and its greater height.  At first sight may be confused with the Common Dandelion (Taraxacum officinale), but, apart from rather different leaves that lack the sharply toothed lobes of the latter, the underside of the ligules are reddish and there are many fewer of them. Phyllaries are purple-tipped and not reflexed. Unlike the Smooth Cat’s Ear, the fruits are of one kind only, tapered at both ends, beaked and noticeably plumose. Can be found in huge numbers.

Common Sow-thistle – Sonchus oleraceus

Blooms:

All year

Plant Height:

10–120 cm

Flower Size:

Medium

Origin:

Europe

Habitat:

Disturbed areas

Notes:

Common. The onion-dome shaped bud is distinctive. The shape of the leaves is extremely variable. Cauline leaves are clasping, the lower ones with clasping lobes with  tips that are acute but not curved or coiled (unlike the rounded and strongly curved or coiled tips of the clasping lobes in Prickly Sow-thistle (Sonchus asper)). The terminal lobe of the cauline leaves is often widely arrow-shaped.  Fruits have 2–4 ribs and are cross-wrinkled. The plant can grow very tall (as much as 6–8 feet) although 2–3 feet is more usual.

Prickly Sow-thistle – Sonchus asper subsp. asper

Blooms:

All year

Plant Height:

10–140 cm

Flower Size:

Medium

Origin:

Europe

Habitat:

Slightly moist, disturbed areas

Notes:

Slightly less common than Common Sow-thistle (Sonchus oleraceus), generally unbranched but with similar flowers and onion-dome shaped buds. The leaves are distinctive, sharply toothed and prickly. Cauline leaves are clasping, the lower ones with clasping lobes that have tips that are rounded and strongly curved or coiled (unlike the acute but not curved or coiled tips of the clasping lobes in Common Sow-thistle).  Fruits have 3 ribs but are otherwise smooth.

Common Dandelion – Taraxacum officinale

Blooms:

All year

Plant Height:

10–40 cm

Flower Size:

Large

Origin:

Europe

Habitat:

Lawns & waste places

Notes:

A very common lawn weed.  Note the large number of ligules compared to the two Cat’s Ears (Hypochaeris sp.). Note also the recurved outer phyllaries which are not found in the Cat’s Ears or the native Dandelions.  The leaves are large, smooth and coarsely serrated. resembling a slightly rounded, barbed arrow-head.

Crete Weed – Hedypnois cretica

Blooms:

Feb–June

Plant Height:

5–40 cm

Flower Size:

Medium

Origin:

Mediterranean

Habitat:

Grassland, roadsides

Notes:

Comparatively uncommon. This is distinguished by its finely bristly leaves which may be entire, toothed or lobed. Petioles of the basal leaves are winged. The peduncle thickens towards the tapering receptacle. Ligules are reddened on the lower surface.

Bristly Ox-tongue – Helminthotheca echioides

Blooms:

Apr–Dec

Plant Height:

30–75 cm

Flower Size:

Medium

Origin:

Europe

Habitat:

Waste and disturbed areas

Notes:

Much-branched with pale yellow flowers.  The bristly phyllaries, stems and leaves are distinctive and amply justify the common name of this rather unattractive plant. Many of the bristles arise from a whitish, pimply base.