Where the acidic soil is poorer on outcrops and well-drained slopes, the ground flora is predominantly bilberry Vaccinium myrtillus and common cow-wheat Melampyrum pratense, a hemi-parasitic annual plant that gains some of its nutrients from roots of nearby host plants, in the Wood of Cree, these are likely to be oak roots. Cow-wheat is an indicator of ancient woodland, as it is a myrmecochorous annual – its seeds are dispersed locally by ants foraging close to their nest. They transport the seeds to feed their larvae with the nutrient-dense elaisomes, attached to the seed, then discard the seed into underground middens where they germinate in Winter, developing roots. In Spring, if the roots have attached well to a host, rapid growth develops above the surface, allowing the plant to flower early. The attachment to tree roots allows the plant to survive on very poor soil and in drought, as they are not reliant on soil moisture.