When temperature and daylength start to increase, the central stem begins to elongate and branch, growing more rapidly. Early sowing allows more time for developing a large rosette and more extensive branching, which results in a higher yield. Flowering is mainly influenced by daylength. The period from the end of flowering to maturity is usually 4 weeks. The total period from sowing to harvest maturity varies with variety, location, sowing time and growing conditions; for June or July sowings, it may be about 26–31 weeks. Both wild and cultivated forms have a diploid set of 2n = 24 chromosomes. Crossings with Carthamus palaestinus, Carthamus oxyacanthus and Carthamus persicus can produce fertile offspring. History Safflower is one of humanity's oldest crops. It was first cultivated in Mesopotamia, with archaeological traces possibly dating as early as 2500 BC. Chemical analysis of ancient Egyptian textiles dated to the Twelfth Dynasty (1991–1802 BC) identified dyes made from safflower, and garlands made from safflowers were found in the tomb of the pharaoh Tutankhamun. John Chadwick reports that the Greek name for safflower (, ) occurs many times in Linear B tablets, distinguished into two kinds: a white safflower (ka-na-ko re-u-ka, , ), which was measured, and red (ka-na-ko e-ru-ta-ra, , ) which was weighed. "The explanation is that there are two parts of the plant which can be used; the pale seeds and the red florets." The early Spanish colonies along the Rio Grande in New Mexico used safflower as a substitute for saffron in traditional recipes. An heirloom variety originating in Corrales, New Mexico, called "Corrales Azafran", is still cultivated and used as a saffron substitute in New Mexican cuisine. Cultivation Climate Safflower prefers high temperatures and grows best at . It tolerates , but there are also some varieties which grow under very low temperatures. Safflower is cultivated in different seasons: as a winter crop in south central India, as an early summer crop in California and as a mid-summer crop in the Northern Great Plains of the United States. Minimum length of the growing season is 120 and 200 days for summer and winter cultivars, respectively. Plant performance is highly dependent on the different planting dates in terms of temperature and day length. Winter hard varieties only form a rosette in late fall and elongates in spring. In early stages, safflower tolerates humidity but after bud stage the danger of a Botrytis