The structure and development of roots haustoria in 37 species parasitic Scrophulariaceae was studied using light microscopy. mature haustorium consists two regions: the swollen "body" parent root, which resembles non-haustorial structure. body arises from root is composed an epidermis, cortex, central region xylem (the vascular core), a parenchyma parenchymatous portion contained host tissue endophyte). core predominately vessel elements. col-lenchyma. Vessels extend through to endophyte....

The initiation and early developmental stages of the haustorium were studied in Agalinis purpurea (Scrophulariaceae). Plants grown a 0.9% agar inorganic medium with 0.5% sucrose supplement. Root exudate collected from Lespedeza sericea induced haustoria, earliest evident 6‐12 hr. A 30‐min exposure to produced an increased frequency haustoria 24‐hr yielded haustorial frequencies equal number that initiated on control plants continuously exposed root for 5‐day growth period. cytological...

Hydnora africana is a root holoparasite of southern Africa that emerges only to flower. The trimerous flowers H. have androecial and gynoecial chambers attract floral visitors with putrid odors emitted from prominent osmophores. We observed phenology insect visitation for at two sites in Namibia evaluated the imprisonment mechanism beetle addition pollen viability assays. Flowers are putatively protogynous 3 d. 18 visitors, including 10 coleopteran species imprisoned by smooth inner surface...

Hydnora is a genus of subterranean holoparasitic herbs found in arid and semiarid regions Africa, Madagascar, the southwestern part Arabian peninsula. Results from field herbarium studies suggest consists four or five species, although more than 12 have been described. The recent rediscovery H. triceps, plant that had remained uncollected for century, supports need additional work. Taxonomic research has impeded by paucity collections, which are often fragmentary nature poorly preserved....

The morphology of the hypogeous root holoparasite Hydnora triceps is highly reduced, and as with many holoparasites, vegetative body difficult to interpret. H. has been historically considered a “pilot root” studded lateral appendages known “haustorial roots.” We found consist rhizome thickened root‐cap‐like structure that covered shoot apical meristem. From meristem, procambial strands originated developed into endarch collateral vascular bundles arranged radially around pith without an...

The phylogeny of closely related species Isoëtes has been difficult to infer using morphological or molecular data. southeastern United States exhibits among the highest diversity species, which likely are result a relatively recent radiation. We used whole chloroplast genome (plastome) sequences diploid taxa in Southeast. entire plastome was well supported across various models evolution. Separate phylogenetic analyses coding regions and introns mostly returned same tree topology as...

In greenhouse studies, the American strain of Striga gesnerioides (Willd.) Vatke, indigo witchweed, was potted with a wide range potential hosts, including some known to be parasitized by this species elsewhere, and agricultural ornamental crops importance in southern United States. The host witchweed very limited no major crop were seriously affected. Based on these it appears that poses little danger agriculture. Other strains parasite likewise shown specific.