Fig. 2
From: Biology and resource acquisition of mistletoes, and the defense responses of host plants
An illustration of the haustorium germination of aerial mistletoes (Decaisnina brittenii and Amylotheca dictyophleba, Loranthaceae) showing their developmental stages. A Mistletoe bird eats the mistletoe berries. B The seed passes safely through a bird’s gut (its body is aligned along the twig and carefully wipes its bottom on the bark beneath) yet stick to branches by mechanical pressure and cements copious viscin to the host branch. C Resembles the other parasitic flowering plants, the strigolactones (SLs) perception by SL receptors triggers the germination of haustorium. D, E Early germination stage; seed mass (sm) attached to host with viscin-covered seed mass (vsm/v), with long hypocotyl (hy) and holdfast (ho) separately attaching to host; later stage, hypocotyl extending, cotyledons emerged, first foliage leaves (fl) produced and establishment of seedling with epicortical root (er) called haustorium and F the mistletoe haustorium has connected with the host xylem inside the branch (figure modified after Ko et al. 2014; Saucet and Shirasu 2016; https://asknature.org/strategy/sticky-berries-adhere-2/ Accessed 1 May 2020)