Diversity of wild medicinal plant resources

Based on the collated results, a total of 204 species of wild medicinal plants were investigated, belonging to 149 genera in 51 families. Among them, ferns accounted for 1.96%, 0.67%, and 0.98% of the total number of plant families, genera, and species, respectively, with one family, one genus, and two species identified. Gymnosperms accounted for 5.88%, 2.01%, and 2.45% of the total number of plant families, genera, and species, respectively, with three families, three genera, and five species identified. Representative medicinal plants include Ephedra sinica Stapf (E. sinica Stapf) and Platycladus orientalis (Linn.) Franco. (P. orientalis (Linn.) Franco.) Monocotyledons accounted for 7.84%, 8.05%, and 7.35% of the total number of plant families, genera, and species, respectively, with four families, twelve genera, and fifteen species identified. Representative medicinal plants include Iris tenuifolia Pall. (I. tenuifolia Pall.), Polygonatum cirrhifolium (Wall.) Royle (P. cirrhifolium (Wall.) Royle), and Polygonatum odoratum (Mill.) Druce. (P. odoratum (Mill.) Druce.) Dicotyledons accounted for 84.31%, 89.26%, and 89.22% of the total number of plant families, genera, and species, respectively, with forty-three families, 133 genera, and 182 species identified. Representative medicinal plants include Glycyrrhiza uralensis Fisch. (G. uralensis Fisch.), Polygala sibirica Linn. (P. sibirica Linn.), Adenophora ningxianica Hong (A. ningxianica Hong), Cistanche tubulosa (Schenk) Wight (C. tubulosa (Schenk) Wight), Cynomorium songaricum Rupr. (C. songaricum Rupr.), Arctium lappa Linn. (A. lappa Linn.), Hyoscyamus niger Linn. (H. niger Linn.), and Gentiana dahurica Fisch. (G. dahurica Fisch.)

Single-species families, oligo-species families (containing 2–10 species), and intermediate families (containing 11–20 species) accounted for a considerable proportion of the medicinal plant families in the region. These three categories together accounted for 98.04% of the total number of medicinal plant families surveyed, with 50 families containing 130 genera and 179 species, accounting for 87.25% of the total number of medicinal plant genera and 87.75% of the total number of medicinal plant species. Only one family with more than 20 species was identified, accounting for 1.96% of the total number of plant families, with 19 genera and 25 species identified, accounting for 12.75% of the total number of plant genera and 12.25% of the total number of plant species (Table 2). This indicates that the medicinal plant species in the region tend to be concentrated in a limited number of families, and the phenomenon of dominant families in the region is evident. The distribution of genera also exhibits the same pattern, with all being single-genera or oligogenera, with Potentilla (5 species) and Artemisia (5 species) being the two genera with the most species, containing a total of 10 medicinal plants, accounting for 4.90% of the total number of medicinal plants.

Table 2 Cataloguing table of wild medicinal plants in the multi-ethnic areas of Gansu–Ningxia–Inner Mongolia intersection

Based on fieldwork and interviews with 105 informants, we classified the medicinal plants into several categories based on their usage parts, including whole plant, root and rhizome, stem and leaf, flower, fruit, and bark. The root and rhizome category has the most medicinal plants, including G. dahurica Fisch., Bupleurum smithii Wolff var. parvifolium Shan et Y.Li (B. smithii Wolff var. parvifolium Shan et Y.Li), P. sibirica Linn., Notopterygium forbesii de Boiss. (N. forbesii de Boiss.), Rheum undulatum Linn. (R. undulatum Linn.), and Cimicifuga foetida Linn. (C. foetida Linn.) The whole plant category includes Artemisia annua Linn. (A. annua Linn.), Taraxacum mongolicum Hand.-Mazz. (T. mongolicum Hand.-Mazz). The fruit category has Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H.F.Chow. (Z. jujuba Mill. var. spinosa (Bunge) Hu ex H.F.Chow.), Hippophae rhamnoides Linn. (H. rhamnoides Linn.) The flower category includes C. tinctorius Linn., and the bark category includes Acanthopanax giraldii Harms (A. giraldii Harms), Lycium chinense Miller (L. chinense Miller) (Lycii Cortex), etc. [8].

Basic information of ethnology information respondents

In addition, we also investigated the basic information of the informants, including their age, gender, ethnicity, and occupation. The results showed that the age of the 105 informants ranged from 19 to 87 years old, with 3 people under 25 years old, 11 people between 25 and 35 years old, 23 people between 36 and 45 years old, 21 people between 46 and 55 years old, 19 people between 56 and 65 years old, and 28 people over 65 years old. Among them, 53 were male and 52 were female, with a gender ratio of nearly 1:1. There were 87 Han informants, 13 Hui informants, and 5 Mongolian informants. Among the 105 informants, 23 had medical experience (including 4 with medical qualifications), 43 had experience in cultivating or operating Chinese herbal medicine, and 3 were forest rangers in natural reserves (Fig. 2).

Fig. 2

Basic information about the interviewees

Utilization of wild medicinal plants in the Hassan Mountain area

A total of 105 respondents provided information on the use of 44 medicinal plants, which involved 50 wild medicinal plant species (some of which have multiple sources), representing only one-fourth of the 204 medicinal plant species discovered during our investigation. These 50 wild medicinal plants traditionally used by local residents belong to 27 families, including one species of fungi (Lasiosphaera seu Calvatia (L. seu Calvatia)) and three species of Ephedra (Ephedraceae), with E. sinica Stapf being the most widely used. Of the 46 species from 25 families of angiosperms, the Compositae family has the most species, with 11 species accounting for 22% of the total number. Among them, E. sinica Stapf, Artemisia argyi Lévl. et Van. (A. argyi Lévl. et Van.)/Artemisia kanashiroi Kitam. (A. kanashiroi Kitam.) (uncertain), A. annua Linn., and T. mongolicum Hand.-Mazz. are the most representative wild medicinal plants in the area. In addition, two medicinal plants (Bian-Bai and Xin-BuGan) were not identified with certainty due to lack of corresponding plant species.

Commonly used medicinal herbs in households include Artemisiae Annuae Herba(A. Annuae Herba), Artemisiae Argyi Folium (A. Argyi Folium), Bupleuri Radix (B. Radix), Glycyrrhizae Radix et Rhizoma (G. Radix et Rhizoma), and Ephedrae Herba (E. Herba) (Fig. 3). These plants are mainly used as whole plant, with 15 species, followed by roots (14 species), stems (8 species), fruits and seeds (7 species), leaves (4 species), and bark (2 species). One particularly unique plant, Euphorbia esula Linn. (E. esula Linn.), is used for its fresh stem juice that oozes from the cut section. However, we did not collect information on wild flower herbs in the area, as local residents use cultivated flower herbs, such as safflower, chrysanthemum, and roses (mainly for consumption).

Fig. 3

Common herbs stored by local residents. A Scutellaria baicalensis Georgi. (S. baicalensis Georgi.) B Glycyrrhiza uralensis Fisch. (G. uralensis Fisch.) C A. annua Linn. D A. argyi Lévl. et Van. (shui Ai). E A. kanashiroi Kitam. (Han Ai). F E. sinica Stapf

The processing methods mainly involve direct sun-drying and cutting, with 35 medicinal plants using this processing method, followed by shade-drying (11 species), fresh use (7 species), and others (3 species). Local residents believe that sun-drying can cause the medicinal odor to disappear, thereby reducing or invalidating the therapeutic effect of the herbs. Therefore, herbs with fragrance are generally shade-dried. In addition, there are some special processing methods, such as the use of A. argyi Lévl. et Van./A. kanashiroi Kitam., which is generally pounded and rubbed into small mountain-shaped moxibustion bars. When used, it is dipped in saliva or water and directly attached to the skin surface using a burning incense stick (Fig. 4). It is removed when the skin feels hot, which is different from the general method used in traditional Chinese moxibustion therapy. Other medicinal herbs used for treating injuries and skin diseases are generally crushed and applied topically with fresh ingredients.

Fig. 4

Moxibustion methods used by local residents. A Wild A. kanashiroi Kitam. B Local residents are making moxa sticks. C Local residents are using moxibustion to treat joint pain

Local residents in the multi-ethnic regions where Gansu, Ningxia, and Inner Mongolia intersect use 50 medicinal plants, but only 27 of them are recorded in the Chinese Pharmacopoeia. Some medicinal plants used by local residents are also recorded in the Chinese Pharmacopoeia, but the sources are different. For example, the local residents use Rhei Radix et Rhizoma (R. Radix et Rhizoma), whose source plants are R. undulatum Linn. and Rheum franzenbachii Munt.(R. franzenbachii Munt.), while B. Radix mainly used by local residents is B. smithii Wolff var. parvifolium Shan et Y.Li, locally known as Xiao-CaiHu. In addition, some of the 50 wild medicinal plants used by local residents are also commonly used as wild vegetables, such as T. mongolicum Hand.-Mazz., Sonchus arvensis Linn. (S. arvensis Linn.), Mulgedium tataricum (Linn.) DC. (M. tataricum (Linn.) DC.), etc. [8].

Quantitative evaluation of wild medicinal plants in the Hassan Mountain area

We quantified the importance of 44 wild herbs traditionally used by local residents in the Hasa Mountain area. The comparison results of the national plant cultural significance index (NCSI) of wild herbs in the region are shown in Table 3 and Fig. 5. Based on the NCSI, we clustered the wild herbs in the area, screened out wild herbs that are widely used, have high value, and play an important role in traditional healthcare among local people. The first important sequence (NCSI > 500) of herbs includes 9 species, representing plants such as Ai (including A. argyi Lévl. et Van and A. kanashiroi Kitam.), Huang-Hao (Artemisia carvifolia Buch.-Ham. ex Roxb. (A. carvifolia Buch.-Ham. ex Roxb.)), Huang-ErCai (T. mongolicum Hand.-Mazz.), Gan-Cao (G. uralensis Fisch.), Da-Yun (C. tubulosa (Schenk) Wight, Boschniakia rossica (Chamisso et Schlechtendal) B. Fedtschenko (B. rossica (Chamisso et Schlechtendal) B. Fedtschenko), etc. The first sequence of wild herbs plays an important role in the lives of local people in the area. They are natural medicines traditionally used by local residents to prevent and treat colds. These herbal resources have a wide distribution, are relatively easy to obtain, have high safety, and are mostly medicinal and edible plants, which are commonly used household items among local residents. The second important sequence (500 > NCSI ≥ 100) of wild herbs includes 15 species, representing plants such as Xiao-CaiHu (B. smithii Wolff var. parvifolium Shan et Y.Li), Huang-Qi (Astragalus chrysopterus Bunge (A. chrysopterus Bunge)), Suo-Yang (C. songaricum Rupr.), Qin-Jiao (G. dahurica Fisch.), etc. The third important sequence (100 > NCSI ≥ 10) of wild herbs includes 9 species, which are mainly plants with special distribution areas or toxic plants, such as Da-Huang (R. undulatum Linn.) of Qiang-Huo (N. forbesii de Boiss.). The fourth important sequence (10 > NCSI) of wild herbs mainly consists of toxic plants that are rare and less commonly used, such as Tian-XianZi (H. niger Linn.) and Tie-BangChui (Aconitum brachypodum Diels. (A. brachypodum Diels.)), etc.

Table 3 Quantitative evaluation index of wild herbs in the multi-ethnic areas of Gansu–Ningxia–Inner Mongolia intersectionFig. 5

Heatmap of medicinal plants in Gansu–Ningxia–Inner Mongolia intersection zone