Many thanks Garg ji. I have suggested my IDs for observations of *Pogostemon speciosus* and *Pogostemon wightii*, purely on the basis of their inflorescence.
Among their inflorescence, which appears dense, and whose rachis can be clearly seen? When comparing the inflorescence of these two species, the visual density and the exposure of the rachis (the central stem of the flower cluster) are two of the most reliable ways to tell them apart in the field. The "Dense" Species: *Pogostemon speciosus* - Appearance: This species is known for its thick, robust spikes. - Density: The flowers are packed very tightly together. Because the individual flowers (corollas) are larger (~7 mm) and more voluminous, they overlap significantly. - Rachis Visibility: The rachis is hidden. Because the whorls of flowers are so close together and the hairs on the calyx are long, you generally cannot see the central stem once the plant is in full bloom. The "Exposed" Species: *Pogostemon wightii* - Appearance: This species has more slender, elongated spikes. - Density: The flower clusters (verticillasters) are often spaced out along the stem rather than being a continuous "wall" of petals. - Rachis Visibility: The rachis is clearly visible, especially between the lower flower clusters. Because the flowers are smaller (~5 mm) and the hairs are appressed (lying flat), the central axis of the inflorescence is much easier to observe. *Summary Comparison* Feature *Pogostemon speciosus* *Pogostemon wightii* *Spike Width* Stout and broad Slender and narrow *Flower Packing* Very dense / Congested Interrupted / Laxer *Rachis* *Concealed* by flowers *Visible* between clusters ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ My suggested ID is *Pogostemon wightii* Benth. The 2nd photo in this post shows the rachis between the cluster of flowers. Garg ji, I hope you agree. Regards. Dinesh On Wed, Feb 25, 2026 at 3:48 PM J.M. Garg <[email protected]> wrote: > Both are quite close. > Dinesh ji, may decide based on the following differences as per Google AI > view: > *Pogostemon wightii* and *Pogostemon speciosus* are both aromatic, > endemic species of the Lamiaceae family found in the Southern Western Ghats > of India. They are similar in appearance and habitat, frequently found in > high-altitude Shola forests (around 1,000–2,200m). > [image: ScienceDirect.com]ScienceDirect.com +2 > The key differences lie in their habit (size/growth form), specific floral > characteristics, and leaf texture. > Key Differences at a Glance > Feature *Pogostemon wightii* Benth. *Pogostemon speciosus* Benth. > Growth Habit Small shrub or herb (sometimes subshrub) Shrub, up to 2 m > tall > Stem/Branching Quadrangular, strigose (stiff, appressed hairs) Pilose-hispid > (hairy) brown branches > Leaf Features Densely strigose, 5-6 cm long, ovate Hirsute, 3-8 cm long, > ovate/orbicular, turn black when dry > Inflorescence 4-8 cm long spikes, continuous Often described as having > "bottlebrush" appearance > Stamens Bearded filaments Lacks moniliform hairs on filaments > Nutlets Biconvex to triangular, smooth, brown Suborbicular, blackish, 1 > mm long > Detailed Breakdown > > - Pogostemon wightii: > - Description: A small, delicate shrub or herb, often found along > stream sides or in marshy spots within Shola forests. > - Appearance: Leaves are smaller (5-6 x 3-4 cm) and intensely hairy > (strigose). > - Flowering: Occurs in December-January. > - Distinctive Feature: Filaments (stamens) are bearded. > - Pogostemon speciosus: > - Description: A more robust shrub, growing up to 2 meters, common > on rocky slopes and degraded areas of the Nilgiri and Anamalai hills. > - Appearance: Leaves are larger and hairy, with the unique > characteristic of turning black when dry. > - Flowering: Occurs from January to February. > - Distinctive Feature: Leaves and stem turn blackish when dried, > and the stamens are very long, giving a "bottlebrush" appearance. > [image: ScienceDirect.com]ScienceDirect.com +4 > > > On Mon, 23 Feb 2026 at 17:27, Dinesh Valke <[email protected]> wrote: > >> >> *FOR VALIDATION ::* >> ¿ *Pogostemon wightii* Benth. ? >> The Nilgiris :: Jan 29, 2026 · 10:11 AM IST >> Kudimalmund, about 2082 m asl >> ------------------------------ >> [image: ¿ Pogostemon wightii Benth. ?] >> <https://www.inaturalist.org/observations/339878715> >> [image: ¿ Pogostemon wightii Benth. ?] >> <https://www.inaturalist.org/observations/339878715> >> [image: ¿ Pogostemon wightii Benth. ?] >> <https://www.inaturalist.org/observations/339878715> >> [image: ¿ Pogostemon wightii Benth. ?] >> <https://www.inaturalist.org/observations/339878715> >> Regards. >> Dinesh >> >> -- >> You received this message because you are subscribed to the Google Groups >> "eFloraofIndia" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion, visit >> https://groups.google.com/d/msgid/indiantreepix/CABSQqC2eP6mASvGneo2BZmatukMMg%3D5FyoOjJAfBD3BgBE_P0A%40mail.gmail.com >> <https://groups.google.com/d/msgid/indiantreepix/CABSQqC2eP6mASvGneo2BZmatukMMg%3D5FyoOjJAfBD3BgBE_P0A%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> > > > -- > With regards, > J.M.Garg, > https://efloraofindia.com/ > -- You received this message because you are subscribed to the Google Groups "eFloraofIndia" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion, visit https://groups.google.com/d/msgid/indiantreepix/CABSQqC0xJDBeQ_Bx%3D3jVrapxC95ZzWwixTsC8KiEouV%2BbSc21A%40mail.gmail.com.
