Taxus celebica

Celebes yew

©
The World Botanical Associates Web Page
Prepared by Richard W. Spjut
April 2003; photos added June 2006; updated August 2007; reformatted June 2010, May 2014

Taxus celebica from Yunnan, Forrest s.n. (A)

Taxus celebica from Tibet (“Assam”), Rima, 7000 ft., Kingdon Ward 19324 (BM)

 

12.  Taxus celebica  (Warb.) H. L. Li (Figs.3B, 23), Woody Fl. Taiwan 34. 1963. Cephalotaxus celebica Warburg, Monsun. I: 194. 1900, one specimen cited—Holotype: INDONESIA. Sulawesi (Celebes): southern, Gipfel des Wawo-Kraeng, on the forest-clad summit, 2800 m, Warburg 16889 S (photocopy!), fragment of type at B that was destroyed.  Warburg distinguished C. celebica from C. sumatrana, and excluded Podocarpus celebicus Hemsl.

            Podocarpus celebicus Hemsley, Kew Bull. 39. 1896. TYPE: INDONESIA. Sulawesi (Celebes): southern, Bonthain Peak, 7000–10,000 ft [Sep. 1895]. A. H. Everett 35 (holotype: K!).

Celebes Yew. Distribution: Forest margins, 1150–3100 m; Nepal, Bhutan, NE India, South Vietnam, China (Tibet, Yunnan, Sichuan), Indonesia (Sulawesi).

Tree 1–20 m high; branchlets yellowish-green to yellowish-red; bud-scales partly persistent, 3-seriate, loosely adnate, minute deltoid, concave and shortly cuspidate, longest ones 0.5–1 mm long, glossy brown, lower carinate, upper smooth, firm. Leaves persistent on older twigs, spreading in two ranks from decurrent petiole 8–20 mm long, not overlapping, nearly parallel, narrowly lanceolate, slightly falcate, 2.5–4 cm long, 3–5 mm wide at widest part of leaf, relatively thinner than most other species, 175–300 µm thick, light green and plane above to a slight, abruptly elevated midrib, pale green and plane below to a flush to slightly rounded midrib, the abaxial marginal region usually (18-) 27–36 cells wide, abruptly differentiated from stomata bands, often not markedly discolored upon drying, mostly with long rectangular epidermal cells, these (3-) 5–15× l/w, thin-walled, not inflated, entirely epapillose, or papillose to one-half of the marginal region; abaxial midrib cells similar, mostly without papillae, or papillose on outer 2–3 rows; papillae medial to submarginal; stomata bands yellowish to distinctively whitish, narrower than the broad marginal and midrib regions; stomata monocyclic, in 11–22 distinct rows/band, each row separated by 1–2 rows of accessory trapezoidal cells with small papillae; upper (adaxial) epidermal cells in transverse section elliptical, ca. 20 µm tall and 25 µm wide, thin-walled; lower (abaxial) epidermal cells not as large, 10–20 µm tall, 20–40 µm wide. Palisade parenchyma 1 row, often short, or indistinct (0–30 µm long). Male cones not seen. Female cones in one specimen plentiful; seed conical, greenish with a dark brown umbo.

     Taxus celebica is recognized by the relatively large, glossy, pale green leaves that have a lanceolate shape, a flattened surface,  plane margins (not revolute), relatively narrow stomata bands in contrast to a broad marginal zone of long rectangular cells, and by other leaf epidermal features as seen in specimens from Sulawesi (type), Yunnan (Forrest 7798), Sichuan (H. Smith 10401, Plate 6 in Florin 1948a), South Vietnam (Schmind s.n.), Bhutan (Cooper & Bulley 2833), Khasia (Clarke 38308) and Tibet (Kingdon Ward 19324).

     The leaf stomata bands of T. celebica have 8–12 (-14) rows of stomata compared to (11-) 14–19 (-21) stomata rows in T. mairei.  The accessory cells are often distinct from other species in the genus by their short wedge shape (<3× l/w) and by the relatively small (minute) medial papillae that are more distant from one another.  The stomata bands are further differentiated by the marginal zone of long rectangular cells (>10× l/w), mostly without papillae across (13-) 24–36 cells, in contrast to the oblong leaves with shorter trapezoidal cells of T. mairei, or the transitional zone of papillose cells that is usually seen in the Baccata and Wallichiana Groups.

     These features of T. celebica suggest a separate evolutionarily line (Sumatrana Group) in which leaf stomata and papillae have become reduced as a result of adapting to warmer climates at lower elevations in tropical areas.  This is undoubtedly related to differentiation of the stomata bands by color—that is clearly evident to the naked eye by the contrast of the reddish discoloration in the marginal and midrib regions (dried leaves), especially T. mairei and T. sumatrana.

     However, one may also argue that T. celebica, along with T. mairei, should be included under T. sumatrana due to various intermediates that are difficult to assign to any species in this group.  My previous annotations of T. celebica were based on leaves having most of the following features: long epidermal cells, obscure palisade layer of parenchyma cells, and flattened shape in T-section, but I have since decided that taxonomic weight should be given to the lanceolate acuminate type of leaf.  This also led to distinguishing T. sumatrana by the puckered leaf in dried specimens.

     An example of a variant of T. mairei that I had earlier considered T celebica differs from T. celebica only by the leaves tapering to an acute or obtuse apex, instead of an acuminate apex—as seen in specimens from Fujian (Price 1258b), Guizhou (Steward et al. 328), Sichuan (Wang 20541), Guangdong (Nanling Expedition 1838), and Ningxia Huizu (Chao 1223).  These specimens belong to var. speciosa, distinguished by the relatively large leaves that are green in dried specimens. Another example of T. mairei has the acuminate leaves of T. celebica (especially young or immature leaves) but differs by their more elliptical instead of lanceolate shape, and by their abaxial midribs having mammillose epidermal cells.  This includes duplicates of the original material for T. mairei from Yunnan (Maire s.n.) and additional specimens from Taiwan (C-j. Chang, from Hua-lien).   The mammillose  epidermal cells as seen in leaf T-sections, often accompanied by a layer of enlarged parenchyma cells lying closely against the midrib epidermal cells, is characteristic of  T. mairei.  Most other specimens of T. mairei further differ by thicker leaves that are more convex across the adaxial surface, and less evenly tapered to an obtuse apex.  The characteristic leaf anatomical features apply to both var. mairei and var. speciosa.

     The leaf anatomical features of long epidermal cells, a broad marginal zone of epapillose cells, and short wedge-shaped accessory cells with minute papillae, have been observed in some T. mairei specimens where cell length and development of papillae may also vary on leaves from the same plants.  For example, a specimen cultivated at Kew Gardens has leaves shaped like T. mairei with stomata bands similar to T. celebica (wedge shaped cells, small papillae, yellowish chloroplast), while a blind study of numerous leaves from a related specimen in cultivation (Phyton s.n.), and also from Taiwan (Hua-lien, Chang 1–5,7-10), the leaf epidermal cells varied in length and in shape in which young leaves were determined to be T. celebica or T. sumatrana. This suggests that T. mairei may have been derived from an ancestral T. sumatrana complex, and it may have also subsequently hybridized with this species—giving rise to many combinations between leaf shape and the anatomical features.  Although development of papillae in the leaf marginal zone is variable within the Sumatrana Group (Appendix), the papillose marginal cells can be easily distinguished from those of the stomata bands.  I interpret this as evidence of papillae having evolved secondarily in the group, consequently, more influenced by environmental factors.

     Taxus sumatrana var. atrovirens is very similar to T. celebica in having relatively large leaves that appear green in dried specimens.  It is distinguished by the puckered leaf, appearing strongly channeled on the adaxial surface along the midrib.   Specimens from the Arnold Arboretum Herbarium under this variety were previously annotated T. celebica.  While this variety appears intermediate to T. celebica, the character feature of the puckered leaf helps tie together T. sumatrana and its varieties, including var. concolorata.  There is the temptation to treat all species as subspecies in the Sumatrana Group under T. sumatrana; however, classifications with subspecies and varieties of a species are in my opinion less useful.  Another alternative is to treat T. celebica as a variety of T. sumatrana, as I have temporarily indicated on this page, but my preference is to maintain this taxon as a distinct species.  On the other hand, because specimens from Nepal and Bhutan appear to intergrade with T. kingstonii, another solution was to treat them as a distinct species for which an epithet was chosen based on the acuminate leaf as indicated in an unpublished key included in a research proposal (April 1995).

Representive SpecimensNepal Harain Letty, 16 Oct. 1902 (BM), 17 Oct 1802 (GH, p.p., left specimen). Bhutan: illegible, 9,000-10,000 ft, Griffith 2006 (K, p.p., with T. wallichiana). India—Khasi Hills, “Mawphlang,” scattered in the evergreen Sacred Grove, 6000 ft, erect tree, Kingdon-Ward 18751 (A); Khasia (Hills), “Maophlang,” Clarke 38308 (K); presumably collected in Khasi Hills, locality illegible, 10 ft high, label from Kew Herb. Hooker, in adnot. Cephalotaxus mannii (GH); Khasi Hills, Nungluai, 6,000 ft, G. Mann s.n. (A, P). South Vietnam: Da Lat: ravin buisé an chalet Rimaud, Evrard 305 (P: 2 sheets); Langfian, Evrard 1438 (P); Da Lat: Dan Tria, Manline, 1400 m, 1610 m, Schmid, yr 1960 (P); same location, Cuong 1289 (P); Dua Lamghi, Schmid, yr 1960 (P). China—Tibet: “Assam,” Rima, 7000 ft., Kingdon Ward 19324 (BM). Yunnan: Forrest 11789 (K); Forrest s.n. (A). Sichuan: W region, between Huangnipu and Yaan (Yachou), Malingtsang, 900 m, H. Smith 10401 (A, BM); vicinity of Wah-hsien, Mou-tao-chi, Metasequoia area, Li-chuan, Jian-Nan-Hsien, Ta-pen-Ying, 3800 ft, in forest, tree, C.T. Hwa 027 (A, K). 

 

Tibet: “Assam,” Rima, 7000 ft., Kingdon Ward 19324 (BM)

Khasi Hills, “Mawphlang,” 6000 ft, Kingdon-Ward 18751 (A)

South Vietnam:  Schmid, yr 1960 (P)

 South Vietnam: Da Lat: ravin buisé an chalet Rimaud, Evrard 305 (P)

South VietnamEvrard 1438 (P)

Sichuan: W region, between Huangnipu and Yaan (Yachou), Malingtsang, 900 m, H. Smith 10401 ( BM).  Image on right reproduced from Kwei, Y-l. and S-y. Hu (1974)—Epidermal features of leaves of Taxus in relation to taxonomy. Acta Phytotax. Sin. 12(3): 329–334, plate 67, Fig. 3, referred to as Taxus speciosa.  Midrib on abaxial leaf surface x 65

Yunnan: Forrest (A).

 

Yunnan: Forrest 11789 (K)

Sulawesi: Type for Podocarpus celebicus (K)

Bhutan: illegible, 9,000-10,000 ft, Griffith 2006 (K, p.p., with T. wallichiana), intermediate to T. kingstonii.

Bhutan: Ronchu Pinakka, 6,000- ft, Cooper & Bulley 2833 (BM).

Nepal Harain Letty, 16 Oct. 1902 (BM), 17 Oct 1802 (GH, p.p., left specimen, with T. kingstonii), intermediate to T. kingstonii.

 

 

General features of the Taxus sumatrana Group

Key to Species and Varieties in the Taxus sumatrana Group

References: see Introduction to Taxus, Overview of the genus Taxus, and Spjut 2007a, 2007b.

Spjut, R. W. 2007a. A phytogeographical analysis of Taxus (Taxaceae) based on leaf anatomical characters.  J. Bot. Res. Inst. Texas 1(1): 291–332

Spjut, R. W. 2007b. Taxonomy and nomenclature of Taxus.  J. Bot. Res. Inst. Texas 1(1): 203–289.