Linum bienne Linum bienne Linum bienne, the pale flax, is a flowering plant in the genus "Linum", native to the Mediterranean region and western Europe, north to England and Ireland. Pale flax grows as a biennial or perennial plant in dry, sunny calcareous or neutral grasslands from sea level up to 1000 m. It has long, narrow stems to 60 cm tall and slender leaves 1.5-2.5 cm long. The flowers have five petals about 1 cm long and nearly round; they are pale blue but streaked with darker colour. It flowers in late spring and, at least in more temperate regions, through
The Different Forms of Flowers on Plants of the Same Species reflections indicate the economy of nature through a process of gradual modification of plants, their structures being modified and degraded for the purpose of the large scale production of seed which is necessary and advantageous for survival. Darwin states (p. 227): "Cleistogamic flowers ... are admirably fitted to yield a copious supply of seed at a wonderfully small cost to the plant." Francis Darwin indicated that the work on heterostylism had given his father extreme pleasure, especially as it had been one of the most puzzling bits of work he ever carried out. Darwin thought that hardly anyone had seen