Sisyrinchium L.

Sisyrinchium is a genus of ca. 140 species (only 80 according to Goldblatt 2000, Cholewa & Henderson 2002). It is probably limited to the New World and its center of diversity lies in Central and South America. New Zealand species all belong to the related genus Libertia Sprengel (Blanchon & al. 2002). Sisyrinchium angustifolium Mill. is sometimes claimed as native in Ireland (Stace 2010; as S. bermudiana L.) but this is rather unlikely. Evidently, none is native in Belgium (Lambinon & Verloove 2012) but four species, two of which closely related, have been recorded as aliens or garden escapes. Many additional taxa are known elsewhere in Europe. A detailed overview is provided by Parent (1980, 1987).

Recent molecular studies demonstrated that Sisyrinchium is monophyletic (Karst & Wilson 2012).

Although most species have small and unshowy flowers, several are cultivated for ornament. Alexander (1986) cites 19 species and several additional infraspecific taxa for Europe (see also Jäger & al. 2008).

Sisyrinchium is a complex genus in which the species are not always easily distinguished. Branching pattern of stems is a useful feature but, when immature, plants of branched species appear to be simple-stemmed (Cholewa & Henderson 2002). Some taxonomists have thought differences too subtle and chosen to lump species. Two of the species here concerned, i.e., S. angustifolium and S. montanum, have been considered synonymous by several authors.

1       Flowers bright or pale yellow === 2

         Flowers pale or violet blue === 3

2       Flowers bright yellow. Leaves up to 6 mm wide, green. Plant usually small (rarely exceeding 50 cm), with in a terminal cyme === Sisyrinchium californicum

         Flowers pale yellow. Leaves up to 20 mm wide, more or less glaucous. Plant robust (normally exceeding 50 cm), with flowers in terminal and lateral cymes === S. striatum

3       Stem unbranched, with a single terminal inflorescence. Stem with a single node. Flowers violet-blue, 25-35 mm across. Pedicels erect in fruit. Outer spathe 36-76 mm long === S. montanum

         Stem branched, each branch with a terminal inflorescence. Stem nodes usually 2-3. Flowers pale blue (rarely darker), 15-20 mm across. Pedicels arched to pendent in fruit. Outer spathe 18-38 mm long === S. angustifolium


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Cholewa A.F. & Henderson D.M. (1985) Notes and lectotypification of some type specimens of Sisyrinchium (Iridaceae). Brittonia 37(2): 163-164.

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Ravenna P. (2002a) Revisional studies in the genus Sisyrinchium (Iridaceae) VIII. Onira 6: 48-62.

Ravenna P. (2002b) Revisional studies in the genus Sisyrinchium (Iridaceae) IX. Onira 7:  20-40.

Ravenna P. (2003) Revisional studies in the genus Sisyrinchium (Iridaceae) X. Onira 8(6): 20-24.

Ravenna P. (2003) Revisional studies in the genus Sisyrinchium (Iridaceae): XI. Onira, Bot. Leafl. 8(13): 48-54.

Ravenna P. (2004) Revisional studies in the genus Sisyrinchium (Iridaceae) XII. Onira 10: 1-24.

Ravenna P. (2005) Revisional studies in the genus Sisyrinchium XIV (Iridaceae). Onira, Bot. Leafl. 10(20): 65-70.

Ravenna P. (2007) Revisional studies in the genus Sisyrinchium XV (Iridaceae). Onira Bot. Leafl. 11(3): 5-13.

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Ward D.B. (2014) Types of E.P. Bicknell's Sisyrinchium (Iridaceae). Phytoneuron 2014-57: 1-12. [available online at:]

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith