Deutzia hookeriana

Deutzia hookeriana (Schneid.) Airy Shaw, Bull. Misc. Inform. Kew 1934: 180 (1934) (syn: Deutzia compacta var. multiradiata J. T. Pan; Deutzia corymbosa R. Br.; Deutzia corymbosa var. hookeriana Schneid.; Deutzia corymbosa var. purpurascens C. K. Schneid.; Deutzia corymbosa var. staurothrix (Airy Shaw) Zaik.; Deutzia corymbosa var. yunnanensis Franch. ex Rehder; Deutzia hookeriana var. macrophylla S. M. Hwang; Deutzia hookeriana var. ovatifolia S. M. Hwang; Deutzia hypoglauca Rehder; Deutzia staurothrix Airy-Shaw);

S-Tibet, China (NW-Yunnan), Bhutan, Sikkim, Myanmar [Burma] (Kachin), Nepal, Jammu & Kashmir (Kashmir), N-India as per Catalogue of Life;

Keys as per efi thread:
Calyx teeth acute in the key is confusing. However, they look entirely different from each other. Leaves are large in D. corymbosa with green lower surface (Grey in D. staminea). Inflorescence is terminal (axillary panicles in D. staminea).
Deutzia corymbosa : 32 posts by 2 authors. 8 images.
Deutzia corymbosa
May 2018

Your photographs are from UK, where only D. staminea and D. compacta occur. In H.P., only D. staminea and D. corymbosa occur. According to FLORA OF GARHWAL by GAUR, young branches are reddish brown in D. compacta (also in your samples), while brownish in D. corymbosa.
Leaves are comparatively larger in size in D. corymbosa.
I think, your plant is rightly identified and my plant is different.
(They do not have D. corymbosa)

Leaf base rounded or broadly cuneate in D. compacta.
Your images look similar to those at Deutzia staminea R.Br. ex Wall. 
What are the keys ?
Deutzia corymbosa R. Br. is a syn. of Deutzia hookeriana (Schneid.) Airy Shaw as per Catalogue of life.
Details available in Flora of China and FoC illustration.
Both these are closely related as per keys in Flora of China:
9 (8)Leaf blade abaxially sparsely 6-8-rayed stellate hairy, hairs of 2 types (minute and larger ones) 7 D. compacta
+Leaf blade abaxially densely 8-10(-15)-rayed stellate hairy, hairs uniform 8 D. hookeriana
Calyx is different in D.compacta as per FoC illustration and appears different from your post, to me.
Surprisingly, I do not find any stellate hairs on abaxial surface in your image DSCN0168.JPG (in fact, it appears totally glabrous)

No, Sir. These are quite different from D. staminea.
D. staminea is very common species in H.P. and U.K. 
This one very rare. Seen only 2-3 plants during the last 10 years. It is similar to D. compacta occurring in UK and Nepal. 
D. compacta was enlisted at FoI. But, when I sent D. corymbosa to ..., he changed the correctly identified D. compacta to D. corymbosa
Kindly go through the complete thread. There is no error in my ID.
What are the keys given in your books?
I am following Local Floras (Flora Simlensis, Flora of Sirmaur, Flora of Kullu, Flora of Chamba, Flora of Bashahar Himalaya, Flora of Lahul) along with POWO and WFO at present. I do not use Catalogue of Life.
POWO as well as WFO consider these three species (Deutzia hookeriana (C.K.Schneid.) Airy Shaw, Deutzia corymbosa R.Br. ex G.Don and Deutzia compacta Craib) as separate and accepted species. Deutzia staminea is quite different from these. 
Attachments (2)

Leaves of Deutzia staminea (smaller one) and D. corymbosa (larger one) for comparison

Leaves of Deutzia staminea and D. corymbosa for comparison.
Attachments (2)

Deutzia staminea


D. corymbosa

Fruits for comparison
Clicked in June 2018
Attachments (2) 
Thanks, … You can clearly see calyx teeth is acute here and not obtuse as given in the keys for D.corymbosa. I think this is the most important character.

For your posted plant, I will go for Deutzia staminea R.Br. ex Wall. (where calyx is clearly seen).
Kindly see the leaf characteristics, leaf size, abaxial surface and inflorescence type.
I have no confusion between D. staminea and D. corymbosa. However, due
to nomenclatural changes, status of D. compacta, D. hookeriana and D.
may change as they are more similar to each others.
Calyx teeth 
Posting Deutzia staminea separately. 
Calyx teeth is acute. Can you explain why the key states it to be obtuse?

By seeing your other post, calyx looks a bit different, but calyx teeth is still acute.
Pl. see calyx in D.compacta as per FoC illustration  

I agree with your id as D. corymbosa, but keys w.r.t. calyx teeth are not properly worded, causing confusion.
Have you seen my another post on D. staminea?
Attaching information from FLORA OF KULLU which says calyx lobes ovate/obtuse as seen in this case.
Attachments (1)

Yes, … Calyx teeth acute in the key is confusing. However, they look entirely different from each other. Leaves are large in D. corymbosa with green lower surface (Grey in D. staminea). Inflorescence is terminal (axillary panicles in D. staminea).