這山地灌木林與馬鞍山的具特殊科學價值地點非常相似，長時間不受外間干擾。這地點記錄有200多種本地植物，包括許多稀有和受保護的本地植物。物種多樣化的森林在香港很少見，在植物學上具有十分重要的意義。
曾記錄的受保護的植物包括常綠臭椿丶吊鐘花丶香港木蘭丶擬美國薄荷丶香港大沙葉丶豬籠草丶華麗杜鵑丶香港杜鵑及華南青皮木。而曾記錄的其他稀有植物有嶺南槭丶秀柱花及一種新的冬青屬植物。
這種更有不同種類的蘭花，例如香港安蘭丶竹蘭丶石蘭與及因非法採摘而變得非常罕有的紫紋兜蘭。
1983年，中國科學家在大東山發現了一種新的植物香港細辛，該品種亦於婆髻山有所記錄，大嶼山是目前世界上唯一一個記錄有這種植物的地方。

These montane shrub forests are very similar to that at Ma On Shan SSSI. They are undisturbed for a long period of time. Over 200 species of native plants have been recorded and a number of rare and protectedindigenous plants are found. Such diverse forests are now rare in Hong Kong and have great botanical importance.
Protected plants found include Ailanthus fordii (Ailanthus), Enkianthus guigueflorus (Chinese New Year Flower), Magnolia championi (Hong Kong Magnolia), M. fistulosa, Pavetta hongkongensis (Pavetta), Nepenthes mirabilis (Pitcher Plant), Rhododendron farrerae (Farrer's Azalea), R.hongkongensis (Hong Kong Azalea) and Schoepfia chinensis. Other rare plants recorded include Acer tutcheri (Tutcher's Maple), Eustigma oblongifolium (Oblong-leaved Eustigma) and a newly recorded llex species. Apart from Ma On Shan SSSI, Po To Yan is the other site where substantial numbers of Hong Kong Azalea can be found.
There is also a collection of different orchids such as Ania hongkongensis (Purple Bulb Orchid), Arundina chinensis (Bamboo Orchid), Paphiopedilum purpuratum Orchid (Hong Kong Lady's Slipper Orchid) and Pholidota chinensis (Rattlesnake Orchid). The indigenous slipper orchid P.Purpuratum is now very rare due to illegal collections in the past.
Asarum hongkongense, a plant new to science discovered by a Chinese scientist at Sunset Peak in 1983 (Hwang & Wong 1990), is also found in Por Kai Shan. At present Lantau Island is the only place in the world that this plant has been recorded.