原產美國南部，每束葉由兩針葉或三針葉組成，和本地原產的山松兩葉一束不同，樹幹挺直高大，樹冠整齊，山松樹冠較任意自由，球果成熟後瓣狀張開 （即種鱗），鱗有刺， 夏天開始可檢拾成熟掉下的球果。

Native to the southern part of America, it is widely grown in Hong Kong plantations to replace the local Chinese Red Pines destroyed by pinewood nematodes in the 80s.  It differs from the local species in the sense that it has two to three needle leaves clustered at the end of branches, while the latter has strictly two leaves per cluster.  To enable rapid growth, its trunk is straight and ends with a conical and symmetrical green canopy, as compared to an asymmetrical one of the Chinese Red Pine.  Its conical woody fruit opens like flower petals when mature.  Each petal bears a sting.  The thin tabs of seeds are winged for wind-pollination.  The empty pine nuts fall in summer and can be gathered for Christmas decoration!