Asteraceae: Sunflower Family – Heliantheae (Sunflower) Tribe: various tarweeds

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, is further broken down into subtribes, of which 9 are present.  The Madia (Tarweed) subtribe includes various species, most of which have conspicuous glands which give off a distinct, sometimes strong tarry odor.  This page covers a variety of species of widely varying appearance.

Blow-wives – Achyrachaena mollis

Blooms:

Apr–May

Plant Height:

25–40 cm

Flower Size:

Small

Origin:

Native

Habitat:

Moist grassland

Notes:

The fruiting head of Blow-wives is much more striking than its inconspicuous 3–8 yellow ray flowers (which turn red at maturity). The fruit consists of a shiny black body, and the pappus.  The pappus has 10 bright white scales in two series, the 5 inner scales much longer than the 5 outer. Although the fruiting heads are sometimes confused with Lindley’s Silverpuffs (Uropappus lindleyi), both the number and the appearance of the pappus scales are quite different.

Big Tarweed – Blepharizonia laxa

Blooms:

July–Nov

Plant Height:

10–180 cm

Flower Size:

Medium

Origin:

Native

Habitat:

Woodland openings, chaparral, grassland

Notes:

Among the tarweeds, this is unusual in having creamy-white ray and disk flowers, rather than yellow.  Anthers are dark purple.  Stems are erect, with spreading or arched branches.  Branches have conspicuous stalked glands.  The inflorescence has several heads, each with 5– 13 ray flowers, 5– 10 mm long.  Phyllaries are in one series.  Leaves are narrow, up to 15 cm long; the upper leaves are also stalked-glandular.  One needs to be up early to enjoy the flowers at their best, they may be withered by mid-morning.  Photos #2 and 4 by Cliff Halverson.

Tarweed, Big
Tarweed, Big

Fitch’s Spikeweed – Centromadia fitchii

Blooms:

May–November

Plant Height:

5–50 cm

Flower Size:

Medium

Origin:

Native

Habitat:

Dry hills & plains,  inland

Notes:

Centromadias are most easily recognized by their conspicuous spine-tipped peduncle bracts.  Fitch’s Spikeweed has stalked glands on its leaves and peduncle bracts, is consistently hairy and has red to dark purple anthers.  The bright yellow ray flowers are 2-lobed, unlike most tarweeds which are 3-lobed.

Congdon’s Tarplant – Centromadia parryi subsp. congdonii

Blooms:

June–Oct

Plant Height:

10–70 cm

Flower Size:

Medium

Origin:

Native

Rare or Endangered?

Yes –  1b.1

Habitat:

Grasslands and disturbed areas in the Hwy 68 corridor

Notes:

This rare plant is generally low-growing and scented, with yellow-green leaves and spine-tipped peduncle bracts.  Unlike Fitch’s Spikeweed (Centromadia fitchii, see above), the peduncle bracts are glabrous, to more or less coarsely hairy, but seldom glandular.  Heads contain 9– 20 yellow, 2-lobed ray flowers and 40+ disk flowers with yellow or brownish anthers.

Coastal Tarweed – Deinandra corymbosa

Blooms:

May–Oct

Plant Height:

30–100 cm

Flower Size:

Medium

Origin:

Native

Habitat:

Grassland & woodland, at or near the coast

Notes:

This aromatic plant is common, especially by the coast.  The flower heads have 14–35 ray flowers, 24–70 disk flowers and a shallow involucre.  This separates it from Coast Tarweed (Madia sativa) which has only 8–13 ray flowers, 11–14 disk flowers, and a more rounded involucre.  The upper leaves are linear and crowded below the inflorescence, while the lower leaves are pinnately-lobed.  The plant can be found in large quantities.

Three-rayed Tarweed – Deinandra lobbii

Blooms:

May–Dec

Plant Height:

5–70 cm

Flower Size:

Small

Origin:

Native

Habitat:

Dry, interior hills

Notes:

A small, much-branched plant.  The inflorescence is in panicle-like cluster with 3 deep yellow, 3–5 mm ray flowers and 3 disk flowers.  Anthers are red to dark purple. Subtending bracts sometimes partly overlap the glandular phyllaries.  Leaves are gray-green, rough and with stiff hairs. Not to be confused with Slender Tarweed (Madia gracilis) which can sometimes have only 3 ray flowers but which has a differently shaped involucre and a different growth habit.

Hayfield Tarweed – Hemizonia congesta subsp. luzulifolia

Blooms:

Mar–Dec

Plant Height:

5–80 cm

Flower Size:

Medium

Origin:

Native

Habitat:

Disturbed open, grassy sites, chaparral edges

Notes:

This plant, with its 5–11 white ray flowers, white disk flowers and dark purple anthers, might easily be mistaken for Big Tarweed (Blepharizonia laxa, see above). But it can be distinguished in several ways.  Its phyllaries are broader, with a clear central ridge, and much smaller (and often black) glands.  Its buds are very distinctive, with the outer phyllaries having clearly separated tips, which curve towards but do not reach the center.  Most clearly (if they are visible), the fruits are short and fat, no more than 2 × as long as they are wide; quite different from those of Big Tarweed.