Impatiens glauca var. ecalcarata Harsh Singh, 2022

Singh, Harsh, Sharma, Ashutosh & Adamowski, Wojciech, 2022, Impatiens glauca Hook. f. et Thomson-A little known Himalayan species with augmented description and a new spurless variety, Phytotaxa 539 (3), pp. 280-286 : 281-284

Impatiens glauca var. ecalcarata Harsh Singh var. nov. ( Fig. 1 , Fig. 2A, B & C )

Diagnosis:—This new variety is different from its closely allied variety by its spurless lower sepal.

Type: INDIA. Uttarakhand: Kumaon, on way to Sunderdunga glacier, 30.16541 N, 79.98718 E 2400 m, 7.09.2020, Harsh Singh 305876 (Holotype LWG; Isotype LWG)

Etymology: The variety epithet ‘ ecalcarata ’ is derived from ‘e + calcarate’ meaning being without a spur thus presenting spurless nature of named variety.

Flowering and fruiting:—Late June to September.

Habitat and associated species:—The individuals of this species are found growing in moist, shady habitat with boulders along brooklets. Associated species include Girardinia diversifolia (Link) Friis (1981: 145) , Impatiens tricornis Lindl. (1840: 26 t. 9), I. racemosa DC. (1824: 688) , I. laxiflora Edgew. (1846: 40) , Lecanthus peduncularis (Royle) Wedd. (1869: 164) , Pilea scripta (Buch.-Ham. ex D. Don) Wedd. (1854: 187) and Persicaria chinensis (L.) H. Gross. (1913: 269).

Global Distribution:— India, Himachal Pradesh (Districts: Kangra, Kullu, Shimla and Sirmaur) ( Subramani et al., 2014) & Uttarakhand (Districts: Chamoli and Pithoragarh (Upper Kumaon Division)) and Nepal (Sudurpashchim Province, Far West Nepal & Karnali Zone, Mid-Western Nepal). We have excluded Chamba (Himachal Pradesh) as there is only single specimen mentioned from Kilar, Chamba 58761 (BSD) and our examining of that herbarium specimen shows lack of well-preserved flowers to confirm its identity, as it has only single comparatively large differing flower and leaves so it needs confirmation in field.

Additional specimen examined: Uttarakhand, on way to Pindari glacier was earlier observed in 2017 year, 30.16877 N & 79.92510 E, 2500 m, 30.08.2017, Harsh Singh 26172 ( LWG!) [about 15 mature plants]; Kumaon, on way to Sunderdunga glacier, 30.17080 N, 79.92583 E 2400 m, 7.09.2020, Harsh Singh 305874 ( LWG!) (syntype) ; Kumaon, towards Katling , 2600 m, 9.09.2020, Harsh Singh 305882 ( LWG!) (paratype) .

Conservation status:— Impatiens glauca was originally described from Kumaun Himalaya is known to be a Himalayan endemic species distributed in Indian western Himalaya and Nepal. Based on 4 years of field survey from 2017-2020 and literature surveys, 14 populations are known to be existent in the distribution range and each population is estimated to contain an average of less than 100 mature individuals comprising an overall population size of less than 1400 mature individuals. The EOO (Extent of Occurrence) and AOO (Area of Occupancy) is calculated using the online software GeoCAT, as 43,642 and 52 sq.km. respectively. The species distribution area is not severely fragmented and neither does it exhibit extreme fluctuation. However, there has been continuing decline observed in the quality of the habitat due to various reasons like cattle grazing around the habitat at many sites and also because some hiking routes traverse through some of the subpopulation and hence, plants get trampled. Although, the increment in population size in Criterion D is exponential, with 1400 mature individuals this species is just beyond the threshold, the species can be assessed as NT. Based on these facts, Criteria A, C, and E cannot be applied. However, based on Criterion B and D, following IUCN guidelines (IUCN 2019), the species can be assessed as Near Threatened [NT-B2b(iii); D]. We are also of the view that at least some more undiscovered populations may be present in Western and Central Uttarakhand which otherwise forms large distribution gap in between Eastern Uttarakhand and Himachal Pradesh.

Remarks:—Older literature gives erroneous descriptions of flower color in I. glauca . For example, Chowdhery & Wadhwa (1984) describe flowers as “greenish”, and Vivekananthan et al. (1997) as “orange or pale red”. Greenish coloration could be an effect of observation of flower buds or freshly opened flowers.

Observations of living material of I. glauca show that spur in fully open flowers is set at angle 10-30 degrees downward in comparison with lower sepal long axis, not parallel to it, as in drawing in Akiyama & Ohba (1993).

Vivekananthan et al. (1997) and Pusalkar & Srivastava (2018) give much shorter stature for the species: to 70 cm and 30-80 cm high, respectively; however, Chowdhery & Wadhwa (1984) wrote that it is “high herb”, without detailed data. Specimens from western Nepal (Polunin, Sykes and Williams 5052 and Polunin, Sykes and Williams 405) had annotations “to 5 feet high”. Our observations confirm that I. glauca could reach 1.8 m in late monsoon season.

Majority of balsam species has spurred flowers, however there are numerous exceptions. Members of Madagascan section Trimorphopetalum (127 species; Fischer et al. 2017) have always spurless flowers. There are spurless species in North America ( I. ecornuta Gerry Moore, Zika & Rushworth (2012: 60)) , Himalaya ( I. gammiei Hook. f. (1905: 16), I. occultans Hook. f. (1905: 17), I. tuberculata Hook. f. & Thomson (1860: 155); Gogoi et al. 2018) and SE Asia ( I. casseabriae Y.H. Tan, S.S. Zhou & B. Yang (2017: 104) , I. decurva Ruchis & S.B. Janssens (2018: 64) . Several balsams have spurless varieties ( I. radiata var. mindatensis from Myanmar; Akiyama et al. 2018), in some taxa spurred and spurless flowers could be found on the same plant ( I. racemosa DC. (1824: 688) ; Ruchisansakun et al. 2018).

Sterile/abortive inflorescences were observed in Impatiens glauca ( Duthie 1886) , I. cymbifera Hook. (1875: 474) ( Grey-Wilson 1989) and recently in I. sterilis Y.Y. Cong & Y.X. Song ( Song et al. 2021: 48) .

Akiyama & Ohba (2000) described inflorescence of I. glauca as type 9, including multi flowered inflorescences with bracts born in the middle of pedicel.

Figures

FIGURE 1. Impatiens glauca var. ecalcarata: A.; B––Flower side view; C.; D––Flower frontal view; E––Lower sepal; F––Lateral united petals; G––Dorsal petal; H.––Stamen; I––Capsule; J––Seed; K––Leaf dorsal view.

FIGURE 2. Impatiens glauca var. ecalcarata: A––Plant habit; B––Fruiting habit; C––Flower side view; I. glauca var. glauca: D––Plant with sterile/abortive inflorescences; E––Inflorescence with capsules & a flower; F––Flower showing bifid spur; G––Flower buds with bract; H––Flower side view A–C (I. glauca var. ecalcarata) photographs by Harsh Singh and D–H (I. glauca var. glauca) photographs by Ashutosh Sharma.