Abstract
Pollen morphology of 11 Iranian Dracocephalum L. species was investigated using light and scanning electron microscopy to evaluate their taxonomic significance for the infrageneric classification of the genus. Pollen grains of all examined taxa were isopolar, hexacolpate, circular in polar view and spheroidal to prolate in equatorial view (P/E = 1.0?2.0). The smallest pollen grains were observed in D. aucheri (P = 29.7 ?m, E = 22.6 ?m), while the largest pollen was found in D. lindbergii (P = 45.1 ?m, E = 33.7 ?m). The highest and lowest apocolpium index (AI) were measured in D. aucheri (AI = 0.27) and D. surmandinum (AI = 0.08), respectively. Colpus membrane was egranulate in all examined species except for D. multicaule and D. ghahremanii. The main exine ornamentation type was characterized as bireticulate including five different subtypes. The results revealed that the exine ornamentation is a diagnostic character useful for the classification of Dracocephalum.Bangladesh J. Plant Taxon. 22(2): 99-110, 2015 (December)
Highlights
The genus Dracocephalum L. is the second largest genus in the subtribe Nepetinae, tribeMentheae of Lamiaceae family
The diagnostic pollen grain characters of 11 species of Dracocephalum investigated are presented in Tables 2 and 3
Size: The pollen grains were dispersed as monads
Summary
The genus Dracocephalum L. is the second largest genus in the subtribe Nepetinae, tribeMentheae of Lamiaceae family. Dracocephalum is a heterogeneous genus comprising species with calyx glabrous within and not gibbous at base; sinuses between lobes of calyx with swollen folds at base, bracteoles aristately toothed, nutlets elliptic to oblong and areole not curved. The genus Dracocephalum was divided into three subgenera by Budantsev (1987), viz., subg. Dracocephalum including seven sections (stamens included, anthers glabrous), Fedtschenkiella (Kudr.) Schischk. (stamens exserted, anthers glabrous), and Ruyschiana (Mill.) Briq. The members of this genus are well-known as medicinal plants with several uses, such as anti-hyperlipidemic, analgesic, antimicrobial, antioxidant, anticancer and oxidative stress protective activity (Sajjadi et al, 1998; Jahaniani et al, 2005; Sonboli et al, 2008)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
