Taxonomy and Nomenclature

The history of the recognition of this group of plants is written in the names applied to them by various authors over time. The hickories have a relatively tortured nomenclatural history that was well reveiwed by Little (1943). The name "Carya" (from the Greek "karya" which means "nut tree") was given by Thomas Nuttall in 1818 to separate the hickories from the sister genus Juglans, the walnuts. In order to recognize a given species which has been called different names by different authors, synonymies are maintained. Table 2 is an index to the synonymy of the genus Carya.
The present taxonomic organization of the genus is presented in Table 1. Recognition of species generally follows Manning (1978).

Table 1. Taxa recognized as species by the NCGR Carya, listed alphabetically within section.

Sect. Sinocarya
1. C. cathayensis Sarg. Chinese hickory * (probably includes C. dabieshanensis)
2. C. hunanensis Cheng & R. H. Chang. Hunan hickory *
3. C. kweichowensis Kuang & Lu. Guizhou hickory *
4. C. tonkinensis Lecomte. Viet Nam hickory *
5. C. poilanei (A. Chev.) J. Leroy. Poilane's hickory *

Sect. Apocarya
6. C. aquatica (F. Michx.) Nutt. Water hickory
7. C. cordiformis (Wangenh.) K. Koch. Bitternut hickory
8. C. illinoinensis (Wangenh.) K. Koch. Pecan
9. C. palmeri Manning. Mexican hickory

Sect. Carya

10. C. floridana Sarg. Scrub hickory
11. C. glabra (Mill.) Sweet. Pignut hickory
12. C. laciniosa (F. Michx.) Loudon. Shellbark hickory
13. C. myristiciformis (F. Michx.) Nutt. Nutmeg hickory
14. C. ovalis (Wangenh.) Sarg. Red hickory
15. C. ovata (Mill.) K. Koch.Shagbark hickory (includes Carya carolinae septentrionalis (Ashe) Engl. & Graebn. Southern shagbark hickory
16. C. pallida (Ashe) Engl. & Graebn. Sand hickory
17. C. texana Buckley. Black hickory
18. C. tomentosa (Poir.) Nutt. Mockernut hickory

Interspecific Hybrids
1. C. X brownii (C. cordiformis X C. illinoinensis) Sarg.
2. C. X collina (C. texana X C. tomentosa) Laughlin
3. C. X demareei (C. cordiformis X C. ovalis) Palmer
4. C. X dunbarii (C. laciniosa X C. ovata) Sarg.
5. C. X laneyi (C. cordiformis X C. ovata) Sarg.
6. C. X lecontei (C. aquatica X C. illinoinensis) Little
7. C. X ludoviciana (C. aquatica X C. texana) (Ashe) Little **
8. C. X nussbaumeri (C. illinoinensis X C. laciniosa) Sarg.
9. C. X schneckii (C. illinoinensis X C. tomentosa) Sarg. **
10.C. illinoinensis X C. ovata (see Manning 1962)
11.C. cordiformis X C. tomentosa (see Reed 1944) **
12.C. illinoinensis X C. myristiciformis (see Windham 1981).

* = Asian species. Section Sinocarya Cheng & R. H. Chang (in Chang & Lu 1979) has been proposed for all Asian spp. presently in Section Apocarya, with the exception of C. poilanei.
** parentage disputed