Acanthaceae (PDF)

ACANTHACEAE 3817. STROBILANTHES Blume, Bijdr. 781, 796. 1826.马 蓝 属 ma lan shuHu Jiaqi ( 胡 嘉 琪 Hu Chia-chi), Deng Yunfei ( 邓 云 飞 ); John R. I. WoodAdenacanthus Nees; Aechmanthera Nees; Apolepsis (Blume) Haasskarl; Baphicacanthus Bremekamp; Championella Bremekamp;Diflugossa Bremekamp; Goldfussia Nees; Gutzlaffia Hance; Hemigraphis Nees; Hymenochlaena Bremekamp; Lepidagathissect. Apolepsis Blume; Parachampionella Bremekamp; Paragutzlaffia H. P. Tsui; Perilepta Bremekamp; PseudaechmantheraBremekamp; Pseudostenosiphonium Lindau; Pseudostonium Kuntze; Pteracanthus (Nees) Bremekamp; Pteroptychia Bremekamp;Pyrrothrix Bremekamp; Semnostachya Bremekamp; Sericocalyx Bremekamp; Strobilanthes subg. Pteracanthus Nees; S. subg.Sympagis Nees; Sympagis (Nees) Bremekamp; Tarphochlamys Bremekamp; Tetraglochidium Bremekamp; Tetragoga Bremekamp.Herbs, subshrubs, shrubs, [or small trees], isophyllous or weakly to strongly anisophyllous, woody species commonly pliestesial(living for several years then dying after flowering and fruiting). Stems and branches usually 4-angled, often sulcate, basallybecoming woody and hollow with age. Leaves opposite, petiolate or sessile; leaf blade adaxially usually with prominent linear cystolithsand sometimes also abaxially, margin variously dentate, serrate, crenate, undulate, or entire. Inflorescences axillary and/or terminal,bracteate heads, headlike clusters, spikes (sometimes distinctly secund), or less commonly of pedicellate flowers forming anopen panicle; sterile bracts usually resembling reduced leaves and often present in compound inflorescences; floral bracts usuallydifferent from leaves, persistent or caducous as flowers open, very variable in size and shape, sometimes of two types with basalsterile bracts (outermost bracts in a capitate inflorescence) differing from inner or apical fertile ones; bracteoles 2 per pedicel, usuallysmall, sometimes absent. Calyx usually 5-lobed to base, commonly accrescent in fruit; lobes equal or with middle one distinctlylonger than others, sometimes partially fused to form a bipartite or tripartite calyx. Corolla nearly always bluish, rarely white, yellow,or pink, tubular or funnel-shaped, inside glabrous apart from trichomes retaining style except in Strobilanthes parvifolia, S. oresbia,and related species; tube either gradually widened from base or narrowly cylindric and then abruptly widened, campanulate or gibbous;limb 5-lobed; lobes usually ovate, equal or subequal, spreading, contorted in bud. Stamens usually 4 and didynamous (rarely 2,2 fertile with 2 staminodes, or 4 fertile with a central staminode), basally monadelphous; usually 2 filaments distinctly longer thanother 2; anthers included or exserted, 2-thecous; thecae oblong or subspherical, parallel, erect or incurved, glabrous, basally muticous,rarely with connective extended to a mucronate tip; pollen spherical or ellipsoid, echinulate and/or variously ribbed, usuallytricolporate. Ovary oblong to obovoid, 2-locular, with 2(–8) ovules per locule; style filiform, long, slender, simple, sometimes persistentafter corolla falls, retained in place by trichomes on one side of corolla tube; stigma 2-cleft with one branch longer. Capsulecharacteristically oblong to narrowly obovoid but sometimes fusiform to narrowly ellipsoid, (2–)4(–16)-seeded; retinacula strong,curved. Seeds usually ovate or orbicular in outline and lenticular by being flattened, usually pubescent with appressed mucilaginoustrichomes which become spreading when wetted, trichomes caducous in a very few species with seed glabrescent; areola usuallyvery small but occasionally extending as a glabrous area over much of seed surface.About 400 species: tropical Asia; 128 species (57 endemic) in China.Note on indumentum: in many species the young inflorescence, even when a few capsules are present, is glabrous or nearly so. As the inflorescencematures, sessile glands become stipitate and older inflorescences become gland-tipped pilose, a process parallel to the development of glandsand trichomes as the ovary matures into the capsule. The calyx is also accrescent in many species and the apex appears to continue growing, so calyxlobes, which are linear-oblong at anthesis, may become subspatulate in fruit. There is also a tendency for the corolla indumentum to fall as the corollaopens. Corolla indumentum is most easily observed on buds.Note on pollen: fig. 1 and fig. 2 show 18 pollen types found in Chinese Strobilanthes. It should be noted that the pollen of some 20% of Chinesespecies is unknown and the types shown here could be construed as an oversimplification. However, the images do show the range of variation foundin the genus. Two important caveats should be taken into account. Many publications illustrating Strobilanthes pollen from China are marred by theuse of misidentified material. This is the explanation for cases where a different pollen type is given to that in a published source. A second problemrelates to the degree of infraspecific variation in pollen morphology. This is largely unstudied but it is known that some of the more widespread andvariable species are somewhat diverse in their pollen morphology although all plants sampled have pollen of one general type. Species known to havesomewhat variable pollen include S. atropurpurea, S. echinata, S. speciosa, and S. tomentosa.Attempts to divide Strobilanthes (Strobilanthinae sensu Bremekamp) into segregate genera have proved unsatisfactory largely because the levelof homoplasy displayed by morphological characters has to date rendered subdivision impossible. Molecular studies have not yet greatly clarified thesituation because of insufficient sampling, and this too is likely to prove problematic because many species are known only from the type collection orfrom material inadequate for molecular study. Clusters of related species are clearly discernible, but insufficient information is currently available toproduce a satisfactory infrageneric classification. Species in the following account are grouped with morphologically similar and presumably relatedspecies, but the linear sequence and lack of adequate data implies that the order of species is at least partially arbitrary.Strobilanthes lactucifolia H. Léveillé is not treated in the present account because no material has been traced. It is probably not a species ofStrobilanthes. Strobilanthes straminea W. W. Smith (Goldfussia straminea (W. W. Smith) C. Y. Wu & C. C. Hu) from N Myanmar, included in FRPS(70: 169. 2002), is excluded from the present account because no Chinese specimen can be traced. Strobilanthes deutziifolia H. Léveillé is Abeliamacrotera (Graebner & Buchwald) Rehder in the Linnaeaceae (see p. 645). Strobilanthes gentiliana H. Léveillé is Sesamum indicum Linnaeus in thePedaliaceae (see Fl. China 18: 226. 1998). Strobilanthes hypericifolia H. Léveillé is Abelia uniflora R. Brown in the Linnaeaceae (see p. 645).