|
(Last Modified On 5/15/2013)
|
|
|
|
(Last Modified On 5/15/2013)
|
|
Genus
|
Cestrum L.
|
|
PlaceOfPublication
|
Sp. PI. 191. 1753
|
|
Synonym
|
Meyenia Schlecht., Linnaea 8: 251. 1833, non Meyenia Nees in Wall., PI. As. Rar. 3: 75, 78. 1832, Acanthaceae. TYPE: M. fasciculata Schlecht. (= Cestrum fasciculatum (Schlecht.) Miers). Lomeria Raf., Sylv. Tell. 56. 1838. TYPE: L. purpurea Raf. (= Cestrum longiflorum R. & P.). Wadea Raf., Sylv. Tell. 56. 1838. TYPE: W. latifolia Raf. (= Cestrum latifolium Lam.). Habrothamnus Endl., Gen. 667. 1839. TYPE: Based on Meyenia Schlecht.
|
|
Description
|
Unarmed shrubs or trees to 12 m tall with simple or dendritic hairs, some species glabrous; trunks not exceeding 15 cm d.b.h.; twigs glabrous to velutinous, mostly slender. Leaves simple and entire, pinnately nerved, mostly glabrous above and variously pubescent beneath, mostly short petiolate; minor leaves present or not. Inflorescence axillary, sometimes appearing terminal, often bracteate, mostly a congested raceme or panicle but occasionally open or solitary and sessile; pedicels short, bracteolate. Flowers sometimes nocturnally opening and scented; calyx cyathiform to tubular, variously pubescent, lobed less than halfway down, the lobes sometimes unequal, not much accrescent in fruit; corolla tubular or salverform, often slightly zygomorphic, the tube obconical or with a
|
|
Habit
|
shrubs or trees
|
|
Description
|
bulge along its length, the lobes short, often recurved, the location of pubescence often characteristic for species; stamens 5, equal or subequal, filaments inserted along the corolla tube, variously pubescent, geniculate or appendaged, the anthers clustered, included, bithecate, dehiscent longitudinally; ovary on a small glandular disc or short stipe, glabrous, 2-loculed with 4-50 ovules, the stigma included or exserted, small. Fruit a short-stipitate, fleshy or juicy berry, rarely with one or two apical sutures; seeds variable in shape and size; embryo straight or somewhat curved in fleshy endosperm.
|
|
Distribution
|
A genus of 150-250 species in tropical America.
|
|
Note
|
Many, if not all, Old World species have been described on the basis of material introduced from the Americas. Several species are widely cultivated for ornament, but no other uses are known. Cestrum is divisible into two sections, Cestrum and Habrothamnus. The sect. Habrothamnus, of which only C. chiriquianum, C. aurantiacum, and perhaps C. jacaltenanginum are found in Panama, differs from the typical section in its inflated-clavate corolla tube, pointed corolla lobes, many ovules, and white endosperm (yellow in sect. Cestrum). Section Habrothamnus is centered in Mexico and the Antilles and has little or no representation in South America. Section Cestrum may comprise species reduced or evolved from more primitive, Habrothamnus-like ancestors. Within section Cestrum, the obscurity of phylo- genetic trends makes key preparation or establishment of infra-sectional groupings difficult. The last monograph (Francey, 1935-6), while thorough and correct in a classical sense, is very difficult to use. Unwieldy key format and tendency to emphasize leaf characters prevent easy association of species of like morphology, and in this treatment many species were described from insufficient range of material. Cestrum is closely related to Sessea (about 30 species of the Andes), which differs in having dehiscent capsular fruits. Most species of Sessea have densely pubescent calyces and corollas. The distinctions between Sessea and Cestrum are not accepted by all workers, and the two genera are sometimes combined under Cestrum (see Francey, 1935: 49-51). The genus was given its name because of a fancied resemblance to a plant of this name de-scribed by Dioscorides. In Panama, twenty species are recognized. Three of these, C. latifolium, C. megalophyllum, and C. racemosum, are plentiful and occur frequently in neighboring countries. Many of the other species occur either as rarities or in local areas. In addition to the collections cited under the descriptions below, one collection, Gentry 1499 (MO), must be listed as undetermined. The speci- men is in fruit and was collected in August in mountains above Puerto Obaldia, Comarca de San Blas. As this region is almost unknown from a botanical standpoint, and what little is known reveals the presence of many endemic species, it is possible that this collection represents a new species.
|
|
Reference
|
Francey, P. Monographie du genre Cestrum L. Candollea 6: 46-398; 7: 1-132. 1935-6.
|
|
Key
|
a. Adult leaves pubescent beneath. b. Pubescence of branched or stellate hairs. c. Calyx more than 8 mm long; corolla tube more than 15 mm long, glabrous or pubescent outside. d. Filaments inserted above the middle of the corolla tube; corolla tomentose outside ...... 19. C. strigilatum dd. Filaments inserted below the middle of the corolla tube; corolla glabrous. ....... C. jacaltenanginum var. tomentosum cc. Calyx 3-5 mm long; corolla tube ca. 11 mm long glabrous outside ...... 7. C. lanatum bb. Pubescence of simple hairs or wanting. e. Corolla tube more than 25 mm long, mostly pubescent outside; fruits white; veins mostly more than 7 on each side of the midrib, when dry elevated beneath and giving the leaf a conspicuous corrugated appearance -16. C. rugulosum ee. Corolla tube less than 25 mm long, glabrous outside; fruits purplish or black; veins mostly fewer than 7 on each side of the midrib, when dry not giving the leaf underside a corrugated appearance. f. Filaments free from the corolla less than 1 mm; calyx 3 mm long; corolla tube with an abrupt, globose expansion at the apex; fruits to 15 mm' long ...... 1. C. alternifolium ff. Filaments free from the corolla 1.5-2.5 mm; calyx 2-2.5 mm long; corolla tube evenly obconic with little expansion at the apex; fruits to 9 mm long ...... 9. C. latifolium aa. Adult leaves glabrous beneath (or a few scattered minute hairs on the principal veins). g. Filaments with tooth-like appendages near the point of insertion. h. Filaments manifestly dentate near the point of insertion. i. Corolla tube less than 18 mm long; filaments free from the corolla less than 3 mm; stigma exserted. j. Pedicels evident, 1-2 mm long, pubescent; leaves coriaceous ...... 13. C. pittieri jj. Pedicels wanting or very short and glabrous, leaves membranaceous ...... 12. C. nocturnum ii. Corolla tube more than 18 mm long; filaments free from the corolla more than 4 mm; stigma included. k. Corolla ca. 30 mm long; calyx 3 mm long, lobes not reflexed ...... 3. C . co staricen se kk. Corolla ca. 26 mm long; calyx 4.5 mm long; lobes conspicuously re- flexed ......10. C. lewisii hh. Filaments tumid, gibbous, or with a rounded swelling near the point of in- sertion but not manifestly dentate. 1. Corolla and filaments glabrous ...... 2. C. chiriquianum 11. Corolla interior or filaments at least in part pubescent. m. Corolla tube less than 15 mm long; leaves coriaceous ...... 11. C. megalophyllum mm. Corolla more than 19 mm long; leaves membranaceous. n. Calyx more than 8 mm long; twigs puberulent ...... 20. C. warszewiczii nn. Calyx less than 6 mm long; twigs glabrous ...... 4. C. gracile gg. Filaments unappendaged (sometimes pubescent or barbellate). o. Calyx more than 7 mm long ...... 20. C. warszewiczii oo. Calyx less than 6 mm long. p. Corolla tube less than 15 mm long. q. Filaments mostly more than 3 mm free from the corolla; leaves mostly acute to deltoid in the lower third, often very large, in Panama mostly drying black ....... 11. C. megalophyllum qq. Filaments mostly free from the corolla less than 3 mm; leaves mostly rounded or obtuse in the lower portion, seldom drying black. r. Veins mostly more than 10 on each side of the midvein, evenly spaced and parallel ...... 14. C. racemosum rr. Veins mostly fewer than 10 on each side of the midvein, well or ill spaced. s. Venation obscure above, nearly at right angles to the midvein; leaves drying dark above; inflorescences borne on slender twigs ...... 18. C . standleyi ss. Venation prominent, at ca. 450 to the midvein; leaves drying light green, often greyish or yellowish; inflorescences borne on stout mature wood ...... 6. johnniegentrianurm pp. Corolla tube more than 17 mm long. t. Inflorescence an open, slender, pendant panicle, terminal or on elongate axillary shoots; filaments free from the corolla less than 2.5 mm. u. Twigs and inflorescence whitish puberulent; pedicels wanting; plants usually drying with a brownish or greyish cast ...... 15. C. reflexum uu. Twigs and inflorescences glabrous (rarely glabrate); flowers with short but distinct pedicels (note bracteole position); plants usually drying greenish or yellowish ...... 17. C. scandens tt. Inflorescence a congested terminal or axillary panicle of clustered short racemes or panicles; filaments free from the corolla 3 mm or more. v. Filaments free from the corolla ca. 3 mm; corolla tube more than 22 mm long ...... 8. C. langeanum vv. Filaments free from the corolla more than 4 mm; corolla tube less than 20 mm long. w. Pedicels ca. 1 mm long; calyx 3-4 mm long; plants drying dark brown ...... 4. C. gracile ww. Pedicels 3.5-6 mm long; calyx ca. 5 mm long; plants mostly drying bright green ...... 2. C. chiriquianum
|
|
Tag
|
|
|
|
Project Name
|
|
Tag
|
|
|
|