Gazania Linearis

''Gazania linearis'' is a species of flowering plant in the family Asteraceae, with thin linear leaves, native to South Africa.

Description

''Gazania linearis'' is a clumping perennial herb. The leaves are usually slender and linear in shape, and are usually simple (but can sometimes also be slightly pinnate).
The lower leaf margins are rough and spiny-to-ciliate. The upper leaf surface is dull green while the undersides are white woolly/tomentose. The leaves have long, winged petioles and form basal rosettes at the ground around the short branching stem.
(Unlike the type variety of ''G. linearis'', which has linear leaves, the rare variety ''G. linearis'' var. ''ovalis'' has more oval shaped leaves. It is however only known from a small area near Grahamstown.)

The plant produces large, solitary daisy-like flower-heads that are invariably bright yellow. The ray florets may have dark spots near the bases, curl upwards along their edges, and close at night.
The involucre is subcupuliform or obtusely bell-shaped (campanulate) in shape. Both the involucre and scape can be glabrous or setose.
There are usually some parietal bracts arranged around the involucre. Of the terminal involucre bracts, the outer row is linear with setose-ciliate margins, while the inner row is acuminate with membranous-entire margins.
The fruit is a tiny achene covered in very long hairs several times the length of the fruit body.Flora of North America v 19 p 197
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Diagnostic characters

''Gazania linearis'' is very similar in its morphology to '' Gazania krebsiana'', '' Gazania ciliaris'', '' Gazania pectinata'', '' Gazania rigida'' and others. It is partially distinguished from other ''Gazania'' species by a mixture of several characteristics:
* Unlike '' Gazania krebsiana'', the ''Gazania linearis'' outer terminal row of involucre bracts has minutely ciliate margins. The sympatric populations of '' Gazania krebsiana'' tend to have involucres and bracts that are all uniformly smooth (not hairy or ciliate).
* Unlike '' Gazania krebsiana'', '' Gazania pectinata'', '' Gazania rigida'' and many other species, the ''Gazania linearis'' involucre usually has parietal scales/bracts in at least one clear row around its involucre, in addition to the usual rows of terminal scales/bracts around the tip of its involucre.
* Unlike '' Gazania ciliaris'', the ''Gazania linearis'' petioles are not ciliate, its involucre base is slightly intrusive, and the bases of the old dead leaves often persist around the lower stem.

Distribution and ecology

''Gazania linearis'' var. ''linearis'' (with linear leaves) is indigenous to the southern and eastern parts of South Africa, where it occurs from the Eastern Cape (Humansdorp) in the west, eastwards to KwaZulu-Natal Province.

''Gazania linearis'' var. ''ovalis'' (with more oval-shaped leaves) is restricted to a small area near Grahamstown, in the Eastern Cape.Mucina, L., Howis, S. & Barker, N. (2009). Globally grown, but poorly known: Species limits and biogeography of ''Gazania'' Gaertn. (Asteraceae) inferred from chloroplast and nuclear DNA sequence data. ''Taxon'' 58:871-882. 10.1002/tax.583015. p.879

Mixed Gazania cultivars, sometimes identified as ''G. linearis'', have also taken hold as an introduced species in other parts of the world with similar climates, such as in California and New Mexico in the United States; Australia; and New Zealand, where they have been classified as a weed. The plants typically grow on grassy and rocky hillsides. They are also classified as invasive in some areas, including California.

References

External links

Jepson Manual Treatment
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{{Taxonbar, from=Q5529011

linearis
Flora of South Africa
Garden plants of Southern Africa
Taxa named by George Claridge Druce