Discussion
Taxonomy: The new species shares similarities with those
classified under the genus Madaractis DC. Candolle (1838)
initially identified four species (M. glabra DC., M.
pinnatifida DC., M. polycephala DC., M. scabra DC.) in
this genus. Clarke (1876) considered it as a subgenus and included a
total of 17 species. Among them, S. bombayensis (Syn. S.
reticulatus C.B.Clarke) was the only species included under subsectionSub-paleata of section 1 (members of peninsular India). The
subsection is characterised by the presence of sub-paleaceous nature of
pappus which was also observed in S. anjanericus . Other members
of the section found in Maharashtra are S. belgaumensis (Wight)
C.B.Clarke, S. dalzellii C.B.Clarke and S. edgeworthiiHook.f. (Syn. S. tomentosus (Wight) C.B.Clarke). These members
are further characterized by lax corymbs, uniseriate involucre, ray
florets epappose, cypselae of ray florets sometimes abortive, anthers
ecaudate, and pappus rigid and scabrid. Hooker (1881) mentioned two more
species (both occurring in Maharashtra), S. hewrensis (Dalzell)
Hook.f. and S. gibsonii Hook.f. under section Madaractis .S. anjanericus falls under this section; however, none of the
above-mentioned species show supplementary bracts in addition to
uniseriate involucre that sets S. anjanericus apart from the
other species of the group.
Cytogenetics: Cytological information for Senecio is very
scarce in India, covering about 40% of the total species. Within the
section Madaractis (DC.) Hook.f., four species have had their
chromosome numbers identified previously: S. bombayensis (Syn.S. grahamii Hook.f.), S. hewrensis and S. wightii(DC.) Benth. ex C.B.Clarke (Syn. S. saxatilis Wall.) have a
common chromosome number 2n =20 (Gupta and Gill 1979, Gosavi et
al. 2020) while S. dalzellii with n =20 (Matthew and
Matthew 1988). Additionally, the karyotypic formula for S.
hewrensis is reported as 10m (Gosavi et al. 2020) and for S.
wightii , it is 9m+1sm (Matthew and Matthew 1988). Based on the
available information, it is observed that the species of the section
have a base number x =10. S. anjanericus , with a chromosome
number of 2n =20 and a karyotype formula of 10m, appears to have a
close relationship with the other members of group.
Karyotype of S. bombayensis was more asymmetric than S.
anjanericus . Also, bimodality was more conspicuous in S.
bombayensis with the value of ratio of the longest to shortest
chromosome of a complement (R) 2.46 in contrast to 1.74 in S.
anjanericus . The higher values of MCA (10.43) and
CVCL (31.94) in S. bombayensis indicated
variation in chromosome type and heterogeneity in chromosome length of
the complement. This is also reflected in the karyotype formula of the
species, i.e. 9m+1sm and the range in chromosome length,
3.42 – 1.39 µm. High
CVCI (12.60) in S. bombayensis than S.
anjanericus (2.75) reflects the shift of centromere from median to
sub-median position. Additionally, the secondary constriction inS. anjanericus was located on the short arm whereas in S.
bombayensis it was on the long arm.
Conflict of interest: The authors declare that they have no
conflict of interest.
Significance statement: The significance of this study lies in
expanding our understanding of genus Senecio in Maharashtra and
its position. The detailed morphological and cytogenetic analyses
provide essential data for further research on the evolutionary
relationships and ecological roles of Senecio species in the
Western Ghats, emphasizing the importance of the Anjaneri Hills as a
rich biodiversity hotspot.
Data archiving statement: The data associated with this study,
the type and voucher specimens have been deposited in the Herbarium of
Shivaji University, Kolhapur (SUK). Access to this archived data can be
facilitated through appropriate channels, and researchers interested in
further examination or validation of the findings can contact the
corresponding author for access to the materials at SUK.