You rarely see this Argentinian (and Chilean) garden favourite for sale in garden centres. You are more likely to find it in yogurt pots at plant sales and jumble sales and this should serve as a mild warning – people don’t dig up valuable plants to give away, only those that they have too much of!
This is a plant that has a bit of an identity crisis and as well as the (I hope) accepted name of Sisyrinchium striatum I was aware that it was also known as Phaiophleps nigricans, a name I almost preferred because I always get the ‘y’s and ‘i’s mixed up in sisyrinchium! But that is not all. It has had a host of different names including Paneguia striata, Bermudiana striata, Ferraria ochroleuca, Marica striata and Moraea sertula – the last three all genera in Iridaceae that I would hardly have thought were similar enough to consider.
What is curious is that, despite the plant being in cultivation for, probably, centuries, and it is naturalised in the south of England at least, it does not have a common name. Officially the common name is satin flower or pale yellow-eyed-grass but I have never heard those used. There is a variegated form that is a bit more interesting in leaf, called ‘Aunt May’.
Sisyrinchiums are a confusing lot and most of the 150 or so species are found in South America and about a third in North America with a few others in other places! Most are small, grassy plants with starry flowers and some are grown on rock gardens.
The plant itself is a tough perennial that has fans of grey green leaves about 40cm high and 2cm wide. It grows best in light soils in full sun and is not as rampant in heavy clay. In late spring the fans produce a central stems, about 80cm high, with many bracts that contain clusters of rounded buds that open, over many weeks, into pale yellow, six-petalled flowers that have five to seven distinct black lines on the reverse of the outer tepals. The flowers only last a day but there are always lots of open flowers from June to August.
Although all this may seem very desirable, there are a couple of problems. When the leaves die they go black and look very unslightly, especially in winter, but worse is the way it seeds. It is essential that you cut off the spent flower spikes as soon as the last flowers fade to prevent seeds being cast all over the garden. The worst thing you can possibly do is plant it among iris, as I once did! The seedlings will pop up among the iris and it is almost impossible to weed them out, so similar do they look. It was a nightmare!
– you can have too much of a good thing
7/10 – if you have nothing better