Taxus biternata

Delicate branch yew

The World Botanical Associates Web Page
Prepared by Richard W. Spjut
April 2003; photos added May 2006; updated August 2007

20. Taxus biternata Spjut, J. Bot. Res. Inst. Texas 1(1): 264. 2007 (Figs. 2C, 145–146, 265–270)Type: South Korea, Kyog[sang] Prov.: Kyongsan, Nemon-rei, common or abundant, 15 Sep 1917, Wilson 10688, holotype: A! (Fig. 266, with arillocarpia, abaxial leaf with marginal zone of 8–9 smooth cells, 9 papillose cells, stomata 9 rows/band, and midrib lacking papillae (isotypes K!, marginal leaf zone with 6 rows of bare cells and 8 rows of papillose cells, 7 stomata rows, midrib with marginal papillae; US!). 

Taxus microcarpa (Trautv.) Spjut ined. (in adnot.: A, BH, BM, GH, K, NA, P)

Delicate-branch yew. Distribution: In forests, 800–1400 m, China (NE, Manchuria), Russia (SE Region, North Korea, South Korea, Japan.  In NE China dominant in “mixed broad-leaved deciduous and needle-leaved evergreen forests” (Hou 1983). On N Hokkaido (Japan), “fairly common” within a mixed conifer hardwood forest of Picea jezoensis, P. glehnii, Abies sachalinensis, Populus maximowiczii, Acanthpanax ricinifolius, Ulmus japonica, and Acer pictum (Wilson 1916, as T. cuspidata).  Common in cultivation, including Cv. ‘Capitata’ and shrub forms misapplied to T. media Rehder. At the Secrest Arboretum, apparently spreading by seed among native deciduous hardwoods.

Trees or shrubs with erect trunks and horizontal branches, to 30 m high; branchlets often short and much-divided, subpinnately arranged but unequally divided, appearing ternately divided—or with short delicate tertiary branchlets, horizontal or weeping, yellowish green when young, yellowish orange with age; bud-scales closely overlapping in 3–4 ranks, mostly persistent to the 3rd yr, thick, deltoid, concave, medially recurved and incurved towards apex to form a cusp, with an obscurely thickened mid-nerve, ca. 1 mm long, spreading from base of branchlets. Leaves persistent on older twigs, or lacking, green upon drying, two-ranked to apex, linear, straight to slightly falcate, 1–2 cm long, 1–2 mm wide, 150–250 µm thick, pale green and convex above to a rounded midrib that forms a channel along the base of the midrib, pale yellowish-green and concave below to a rounded midrib, revolute near margins 30–90ş in dried leaves, more notably revolute at upper one-third of leaf; upper (adaxial) epidermal cells in T-sect. elliptical, 10–15 µm tall, 25–40 µm wide; lower epidermal cells similar or larger, 10–15 µm tall, 15–25 µm wide, numbering 11–18 between margin and stomata band, mostly rectangular, or incrassate near the stomata band, 3–7× l/w except quadrate in 1–3 rows near margins, epapillose entirely across the marginal region, or marginal region often partially papillose, often epapillose on (6-) 8–18 cells in from the margins, occasionally with obscure papillae on midrib, papillae usually more prominent on marginal cells bordering stomata band, in 2 opposite rows; stomata bands broader than the marginal region, with 7–13 (-16)  stomata rows/band.  Male bud cones globose, ca. 1 mm diam.; scales 4-seriate; sporophylls ca. 14, united into a terete, smooth or obscurely ribbed column, thickened at apex, spreading shortly above, each branch bearing 8–10 lobed, cucculate sporangia. Female cone scales 4–5 seriate; aril red or pink with tinge of white, with a deep cup, drying dark purple; seed subglobose, obscurely angled where tapering to apex in upper half, 4 mm long, 2–4 mm diam.


     Taxus biternata is easily identified by its tree habit with an erect trunk and horizontal diffuse branching (Fig. 33), and by the much divided slender branchlets with two ranked leaves that spread horizontally (Fig. 31, 32). The horizontal diffuse branching not only distinguishes this from T. cuspidata, which has long ascending or recurved branches, but also from a shrub yew originally described as T. baccata var. microcarpa Trautvetter.  A detailed study by Kolesnikov (1935) showed that T. biternata—regarded by him as T. cuspidata—and the shrub yew are parapatric in which they are distinguishable by morphological and ecological characteristics. 

     The shrub yew, T. umbraculifera var. microcarpa, is similar to T. canadensis in layering, but differs in its flat-topped radial growth—as illustrated by Kolesnikov (1935), and by the much smaller paler seed, shaped like a “Hershey Kiss.”  Additionally, I include other variation in this taxon based on phyllotaxy.

     Occasional specimens of T. canadensis from North America (e.g., Travis 119, Maine, PH), Estonia (e.g., Lundström 742, S), and others from Europe  (e.g., Handel Mazzetti, Mt. Olympus, Greece, K) and SW Asia (e.g., Davis 13667, Turkey, K), treated as T. baccata var. washingtonii (Hort. ex Bot. Berjianus, annot. Florin, S), are similar to T. biternata in features such as the two ranked leaf arrangement, the linear leaf shape, and leaves appearing more strongly revolute in the upper third.  These differ, nevertheless, by color of branchlets—appearing dark green to yellowish green in T. canadensis and yellowish orange in T. biternata.  Taxus canadensis also differs from T. biternata in a number of features such as seed developing on the 2nd yr branchlets, isodichotomous branching, leaves overlapping more closely along one side of branchlet in pressed specimens, falcate leaf shape, and more papillose cells across marginal zone of leaves. Despite these differences, the similarity in branching and phyllotaxy is still remarkable.<

     In SE Manchuria T. biternata appears to hybridize with T. umbraculifera var. microcarpa and var. umbraculifera.  Plants with linear leaves (10× l/w or more) that are strongly recurved in upper third are referred to T. biternata.  Those with relatively short leaves (oblong, 5–8× l/w) are referred to var. microcarpa.

     Taxus biternata can be difficult to distinguish from Taxus cuspidata, the name that many authorities might apply to this species However, the recurved branchlets and upwardly pointed leaves of T. cuspidata are worthy of separate taxonomic status as emphasized by others (Bailey 1933; Hatfield 1921; Rehder 1940). The evolutionary significance of secund leaves is discussed under T. caespitosa.   Branches of T. cuspidata are thicker and more rigid, compared to those of T. biternata, and the dried leaves in specimens from Japan and Korea are more uniformly recurved to revolute along margins, whereas those of T. biternata are more revolute in the upper third (appearing as if pinched slightly)—a useful taxonomic feature for identifying this species.

     The lectotype of T. cuspidata, and other specimens from Japan, also have conspicuous carinate bud-scales that Siebold and Zuccarini (1870) considered diagnostic for this species, in contrast to smaller scales of T. baccata, but this does not hold true as a clear diagnostic feature for separating all yews in E Asia from those in the Euro-Mediterranean as these authors and Rehder  (1940) have indicated (see also Cope 1998 for illustrations of bud-scale features); the differences between the type specimens of T. baccata and T. cuspidata seem less significant when many specimens are taken into consideration across the geographical range of the species, while cuspidate axillary bud-scales are also seen in specimens from Europe.  

     Taxus biternata is common in cultivation as a tree or shrub. I have observed both male and female trees growing apparently wild at the Secrest Arboretum where their origin and identification have been a mystery (Kenneth Cochran, pers. comm. Nov. 1992, accompanied by J. Thieret, M. Hils).  It is also cultivated in other arboreta such as in Sweden (Anderberg s.n., S), and at the Forestry Research Institute in Seoul (Republic of Korea).  The tree forms are easily recognized, whereas shrub forms seem to intergrade with T. cuspidata. This species has also been referred to as T. media based on specimens I have received from Phyton (Ithaca, MY), and those labeled at the Secrest Arboretum (e.g., cv  'T. media Green Wave', A29-80). While leaves of T. biternata are distinctly “two-ranked,” a character feature emphasized by Rehder (1923) for recognizing T. media, the leaves in the type of T. media differ in having darker and thicker (lip-like appearance) margins, which are not recurved (compare close-up photos in key), and they also frequently crisscross instead of spread mostly parallel to each other.   Specimens from the Forestry Research Institute in Korea show additional variation in bark that merits further study.  The cv. 'Capitata' as shown in Hatfield is probably this species as I have also determined from a specimen at the Secrest Arboretum that had this name.

Representative SpecimensRussian FederationFar East Region: Pryanyk For. Div., Zalese Village, silver fir-cedar-broad-leaved forest, B. Cerereu (in Russian, A). ). [Azerbaijan?] Kura Mts.? in Russian #75 (P). Manchuria: Northern, Sochintzest, forest, small trees 20 Sep 1931, Skvortzov s.n. (A). Sikhote-Alin: R.a., foothills of Mount Hezalaza, valley of River Beryozovoy, mixed forest, Lyubarsky 2 (in Russian, A). Manchuria (Mandshuria) SE: Ex herb. hort. bot. Petro. yr 1860, Maximowicz (A). ChinaJilin (Kirin), 5 Sep 1931, C. H. Chen 539 (A); Northern China {Shaanxi: Tai-pei-shan fide Rehder & Wilson in Sargent 1914], Purdom s.n. (GH); Mandshuria SE, ex herb. hort. bot. Petropolitani, 1860, Maximowicz, iter secundum (A, US). [South] Korea. Kyog[sang] Prov.: Kyongsan, Nemon-rei, common or abundant, Wilson 10519 (A, BM, US), Wilson 10688 (A, BM); N. Heian Prov., O.G.M. Co. Mines, Pukchin & Takkari, 833–1000 m, not uncommon in moist forests, 22 Jun 1917, Wilson 8685 (A, K, US); Shinkabachin Heizanchien to Ehoshin, Kankyo-N Heian divide, rare, 5 Sep 1917, Wilson 9097 (A); Seoul, East Palace Park 24 Sep 1905, Jack s.n. (A). JapanHokkaido: Cosl Mines, Utishini, tree 40–5 x 2 (degree sign, ft?), 20 Sep 1892, Sargent s.n. (A); Aza-akaigawa in Morin-machi, 42.0N 140ş39'E, near stream in open woodland, 200 m, tree, 20 ft, seeds embedded in reddish aril, Meyer et al. 19261 (NA); Teshikaga-Machi, 3.2 km SE of Lake Kusharo, road 243, Kawakami-gun, Kushiro, 43.35 N, 144.23 E, Meyer et al. 19112 (NA); Hokkaido, Kitami prov., common in moist woods, tree 15 m x 1.5 m, 17 Aug 1914, Wilson 7399 (A).  Honshu: Sernja prov., Yamanaka on Fuji-san, abundant, tree 6-13 m x 1.5-2.6 m, 4 Nov 1914, Wilson 7778 (A, K); Kai prov., around village of Nakaihinsen, common hedge 18 Sep 1914, Wilson 7544 (A); Nagano-ken, Okmachi, 27 Aug 1951, Uno 2611 (BH, A); Yokohama, ex Herb. Hort Petro., Maximowicz (P); Kamikawa, Nitzelius (S: C-2111); Tokyo Pref.: Oizuni, Nepymawku Makino 43775 (S: C-2111); Mt. Kiyosumi, Makino 43779 (S: C- 2122); Sapporo, Yezo, 21 Jun 1903, Arimoto s.n. (A). Hida, Takayama (A); Shimano Togakushi, 16 Sep 1907 (US:1311890). CultivationOhio, Secrest Arboretum: tree growing naturally outside the arboretum yew plot among native hardwoods and introduced conifers, 10-15 m high, bole 20–5 cm diam., Spjut 12179 (wba).  Japan: cult., Mino Prov., Shiota 4441 (A); Yokahama, ex Herb. hort. bot., Petro., Maximowicz, 1862 (A); Kagoshima Pref., Mt. Takahuma, in forest, tree to 5 m, Hatusima 13858 (A).


Korea: Wilson 10688 (A): Specimen (top left), close-up of male (top right) and separate specimen with seed (bottom).  Observe much divided branchlets and the leaves that appear pinched inwards in their upper third.

Japan: Honshu: Sernja prov., Yamanaka on Fuji-san, Wilson 7778 (A)

Russian FederationFar East Region: Pryanyk For. Div., Cerereu (A).

ChinaJilin (Kirin), C. H. Chen 539 (A).


JapanHokkaido: Cosl Mines, Utishini,  Sargent s.n. (A)

Japan: Honshu: Mt. Nantai, Lake Chuzhen, Mochizuki (A).


Russian Federation: Collector Undetermined.   [Azerbaijan?] Kura Mts.? in Russian #75 (P).  Leaf sections were recorded to have an abaxial margin of 8 smooth cells followed by 9 stomata rows in a band.


Manchuria: Northern, Sochintzest, forest, Skvortzov s.n. (A)