Premna L.

First published in Mant. Pl. 2: 154 (1771)
This genus is accepted
The native range of this genus is Tropical & Subtropical Old World to Pacific.

Descriptions

Timothy M. A. Utteridge and Laura V. S. Jennings (2022). Trees of New Guinea. Kew Publishing. Royal Botanic Gardens, Kew

Distribution
About 50 to 200 species, in tropical and subtropical Asia, Africa, Australia and Pacific Islands; in New Guinea five species are recognised.
Morphology General Habit
Trees to 20 m, shrubs or woody lianas, rarely small herbs
Morphology Leaves
Leaves simple, (sub)opposite or in whorls of 3–4, base without conspicuous glands; petioles not swollen at either end
Morphology Reproductive morphology Inflorescences
Inflorescences terminal, lax to (very) dense cymes or corymbs
Morphology Reproductive morphology Flowers
Flowers: calyx tubular or cup-shaped, slightly or not accrescent in fruit, actinomorphic to sometimes 2-lipped; corolla funnel- or salver-shaped, not greatly enlarged at throat, 2-lipped (occasionally more or less actinomorphic), 4–5-lobed (rarely 1–3-lobed), posterior lip usually entire, rarely 2-lobed, anterior lip 3-lobed, the 2 lateral lobes usually distinct from the larger median lobe, inner surface densely white hairy; stamens 4, didynamous, exserted, hairy at base; ovary, (2–)4-locular, each locule with 1–2 ovules, sometimes only 1 ovule developing, the others suppressed, style terminal, stigma 2-lobed
Morphology Reproductive morphology Fruits
Fruits drupaceous, globose or obovoid, not lobed, indehiscent, 4-seeded or 1-seeded by abortion.
Ecology
In New Guinea, species of Premna occur in primary habitats, but more commonly secondary vegetation, as well as coastal and beach communities; from 0–1800 m.
Recognition
Premna serratifolia is often grown as an ornamental in gardens and as a street tree. The genus can be easily recognised by the unpleasant smell of the crushed leaves, and the corolla with dense white hairs exserted from the tube.
[TONG]

Harley, R.M. et al. (2004). Labiatae, in The Families and Genera of Vascular Plants (K. Kubitzki, ed. in chief) VI: 167-275. Springer-Verlag, Berlin, Heidelberg, New York.

Morphology General Habit
Trees, shrubs or lianas, rarely small herbs
Morphology Leaves
Leaves simple
Morphology Reproductive morphology Inflorescences
Inflorescence terminal, cymose, compound, lax to dense, flowers purplish or white
Morphology Reproductive morphology Flowers Calyx
Calyx tubular or campanulate, truncate or toothed, often obscurely 2-lipped
Morphology Reproductive morphology Flowers Corolla
Corolla infundibular, 4-lobed, 2-lipped (occasionally ± actinomorphic)
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens 4, inserted in middle to lower part of tube, slightly exserted, thecae parallel or divergent
Morphology Reproductive morphology Flowers Gynoecium Ovary
Ovary bicarpellate, syncarpous, 4-locular with one ovule in each locule
Morphology Reproductive morphology Flowers Gynoecium Style
Style terminal with two short stigmatic lobes
Morphology Reproductive morphology Fruits
Fruit drupaceous, with hard pyrene with four seeds.
Note
Numbers of species vary from 50 (Mabberley 1997) to 200 (Verdcourt 1992).
Distribution
Tropical and subtropical Asia, Africa, Australia and Pacific Islands.
[LKGF]

Verbenaceae, B. Verdcourt. Flora of Tropical East Africa. 1992

Morphology General Habit
Trees (sometimes of timber dimensions), shrubs, climbers or rarely small pyrophytic herbs, glabrous to densely hairy
Morphology Leaves
Leaves opposite or in whorls of 3–4, usually distinctly petiolate, entire or toothed, often dotted with resinous glands
Morphology Reproductive morphology Flowers
Flowers hermaphrodite or polygamous, mostly small and dull-coloured, usually numerous in corymbs or thyrses of cymes
Morphology Reproductive morphology Flowers Calyx
Calyx small, campanulate or cupular, truncate or 2–5-lobed and often ± 2-lipped, somewhat accrescent in fruit
Morphology Reproductive morphology Flowers Corolla
Corolla-tube shortly cylindrical; limb spreading, with 4 rounded equal or subequal lobes; throat often hairy
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens 4, ± didynamous, included or less often ± exserted
Morphology Reproductive morphology Flowers Gynoecium Ovary
Ovary 2-locular or spuriously 4-locular; ovules 4, 1 or 2 per locule, attached laterally
Morphology Reproductive morphology Flowers Gynoecium Style
Style subulate, shortly bifid at the apex
Morphology Reproductive morphology Fruits
Drupes small, globose, with thin fleshy mesocarp and bony endocarp; pyrene 4-locular; calycine cup persistent, often venose
Morphology Reproductive morphology Seeds
Seeds oblong, with albumen.
[FTEA]

de Kok, R. 2013. The genus Premna L. (Lamiaceae) in the Flora Malesiana area. Kew Bulletin 68: 55. DOI https://doi.org/10.1007/s12225-013-9433-5

Morphology General Habit
Trees, shrubs, lianas or rarely herb-like with twigs visible above ground and a short woody stem below ground, no exudate
Morphology Twigs
Twig often with a ridge between petioles, glabrous to velutinous, base of young twigs sometimes surrounded by bracts
Morphology Leaves
Leaves simple, opposite to alternate or in whorls of 3 − 4, often aromatic when crushed; hairs simple to stellate or dendroid
Morphology Reproductive morphology Inflorescences
Inflorescences terminal, flowers in lax to (very) dense corymbose cymes, rarely a spike
Morphology Reproductive morphology Flowers Calyx
Calyx tubular or cupuliform, two-lipped or sometimes actinomorphic, 4 or 0 – 5-lobed; lobes isomorphic to heteromorphic, slightly accrescent or not, inside with a ring of long hairs inserted at the place of stamen attachment
Morphology Reproductive morphology Flowers Corolla
Corolla two-lipped (occasionally ± actinomorphic), (4 –) 5-lobed, upper lip usually entire, rarely two-lobed, lower lip three-lobed, with median lobe (lip) largest; stamens 4, equal to slightly didynamous, slightly exserted from the tube; pollen 3-colpate (Raj 1983; Mathew & Shaw 1988); ovary (2) – 4-locular with 1 – 2 ovules per loculus, sometimes only one ovule developing, the other three suppressed (P trichostoma group, see Table 1), stigma 2-lobed; fruit drupaceous, globose or obovoid, remaining undivided; fruit 4-seeded or 1-seeded by abortion, endocarp smooth to warty or with ridges; seeds exalbuminous to albuminous.
Distribution
Tropical and subtropical Asia and Africa, northern Australia and the Pacific Islands.
Ecology
Occurring in evergreen, deciduous or secondary forests, in open vegetation, often along streams and on beaches; alt. 0 – 2600 m.
[KBu]

M. Thulin et al. Flora of Somalia, Vol. 1-4 [updated 2008] https://plants.jstor.org/collection/FLOS

Morphology Reproductive morphology Flowers Corolla
Corolla-tube shortly cylindrical; limb spreading, 4(–5)-lobed
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens 4, usually included
Morphology Reproductive morphology Flowers Gynoecium Ovary
Ovary 2-celled with 2 ovules in each cell; style terminal, shortly 2-fid at the apex
Morphology Reproductive morphology Fruits
Fruit a small globose to ovoid drupe; stone 4-celled.
Distribution
Some 130 species in tropical and subtropical parts of the Old World.
Morphology General Habit
Shrubs or trees
Morphology Leaves
Leaves opposite or in whorls of 3–4
Morphology Reproductive morphology Inflorescences
Flowers mostly small and numerous, in panicle- or umbel-like cymes
Morphology Reproductive morphology Flowers Calyx
Calyx bell- or cup-shaped, truncate or 2–5-lobed
[FSOM]

Flora Zambesiaca. Vol 8, Pt 7. Avicenniaceae, R. Fernandes. Nesogenaceae, M.A. Diniz. Verbenaceae, R. Fernandes. Lamiaceae, R. Fernandes. 2005.

Morphology General Habit
Trees shrubs climbers or subshrubs, glabrous to densely hairy Trees shrubs climbers or subshrubs, glabrous to densely hairy.
Morphology Reproductive morphology Flowers Calyx
Calyx cupuliform or campanulate, usually actinomorphic, truncate to 3–5-dentate or 2–5-lobed, or sometimes c. 2-lipped, somewhat accrescent in fruit Calyx cupuliform or campanulate, usually actinomorphic, truncate to 3–5-dentate or 2–5-lobed, or sometimes c. 2-lipped, somewhat accrescent in fruit.
Morphology Reproductive morphology Flowers Corolla
Corolla hypocrateriform; tube short, infudibular or cylindric, villous or with a ring of hairs; limb 2-lipped, with the posterior lip 2-fid or emarginate and the anterior 3-fid or 3-partite, with the lobes subequal or the median one the largest, or ± regularly 4-fid Corolla hypocrateriform; tube short, infudibular or cylindric, villous or with a ring of hairs; limb 2-lipped, with the posterior lip 2-fid or emarginate and the anterior 3-fid or 3-partite, with the lobes subequal or the median one the largest, or ± regularly 4-fid.
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens 4, didynamous or subequal, inserted near or at the throat of corolla tube, included or ± exserted; anthers dorsifixed, ovoid or subglobose, with divergent thecae Stamens 4, didynamous or subequal, inserted near or at the throat of corolla tube, included or ± exserted; anthers dorsifixed, ovoid or subglobose, with divergent thecae.
Morphology Reproductive morphology Flowers Gynoecium Ovary
Ovary 2-locular with 2 ovules per loculus, or 4-locular by means of false septa and each locule 1-ovulate; style filiform subequalling the stamens; stigma 2-fid
Morphology Reproductive morphology Fruits
Fruit drupaceous, small, with a thin fleshy mesocarp and bony endocarp; pyrene 4-locular or 2–3-locular by abortion; calycine cup persistent, often venose  Seeds oblong, without albumen. Fruit drupaceous, small, with a thin fleshy mesocarp and bony endocarp; pyrene 4-locular or 2–3-locular by abortion; calycine cup persistent, often venose Seeds oblong, without albumen.
Morphology General
A shrub 3–4 m tall; branches with pronounced nodes; flowers apparently borne on leafless branches
Morphology Leaves
Leaves (of which only 3 individual fallen leaves seen) 6.8–10 × 4–6.9 cm, elliptic.oblong, shortly acuminate at the apex, rounded-truncate at the base, entire or only slightly undulate-crenate toward the apex, uniformly hairy on both surfaces, with hairs straight and ± spreading, those on the nerves appressed antrorse, the blades sub-chartaceous and darkly concolorous on drying; petiole 2.6–3.5 cm long, slender, puberulous Leaves petiolate, opposite or 3–4-whorled, simple, entire or dentate, often with minute spherical glands and aromatic when crushed Leaves petiolate, opposite or 3–4-whorled, simple, entire or dentate, often with minute spherical glands and aromatic when crushed.
Morphology Reproductive morphology Inflorescences
Corymbs terminal, somewhat dense, up to 4.5 × 6 cm, the inflorescence branches, pedicels and peduncle densely shortly sub-appressed hairy; peduncle 1–2 cm long; bracts linear-subulate, the lower ones 5–7.5 mm long, the upper shorter Inflorescences terminal, usually many-flowered, with flowers in cymes corymbosely, racemosely or paniculately arranged, rarely the inflorescences axillary Inflorescences terminal, usually many-flowered, with flowers in cymes corymbosely, racemosely or paniculately arranged, rarely the inflorescences axillary.
Morphology Reproductive morphology Flowers
Flowers not opened; calyx puberulous. Flowers hermaphrodite or polygamous, small and dull-coloured Flowers hermaphrodite or polygamous, small and dull-coloured.
Ecology
In open deciduous forest; c. 60 m.
Note
Moldenke, in 1966, determined Mendonça 1004 as P. hildebrandtii Gürke, in an annotation on the specimen label.  However, this material differs from P. hildebrandtii in its sparser indumentum (not velvety tomentose on the leaves as in P. hildebrandtii ), with further differences seen in the leaf shape, the relatively shorter petioles and the smaller inflorescences, the latter corymbose and not paniculate as in P. hildebrandtii .  Moldenke (loc. cit.), perhaps on the basis of Mendonça 1004, cited P . hildebrandtii as occurring in Mozambique (Cabo Delgado), but as yet no material of this species is known from Mozambique.  He also recorded P. hildebrandtii for Zimbabwe (op. cit.: 248), but all Zimbabwean material seen of the genus Premna belongs to P. senensis Klotzsch.  Mendonça 1004 approaches P. serratifolia and P. velutina in the shape and colour of the leaves and in the similarity of the corymbs, but differs from both in the leaf indumentum and the relatively longer petioles.
Distribution
Known only from Mozambique. District code: MOZ N, MOZ N, MOZ M. A genus of c. 226 species and infraspecific taxa (fide Moldenke & A. Moldenke , 1983) * , native mainly in Old World tropics and subtropics, Africa, Asia, Australia, Oceania and extending into China and Japan. Mozambique Mozambique Mozambique
Morphology Reproductive morphology Flowers Gynoecium Pistil
Ovary 2-locular with 2 ovules per loculus, or 4-locular by means of false septa and each locule 1-ovulate; style filiform subequalling the stamens; stigma 2-fid.
[FZ]

Uses

Use
The wood of the bigger species is sometimes used in house building or in the making of furniture or tools, as the wood is durable and resembles teak (Burkill 1935).
[KBu]

Sources

  • Flora Zambesiaca

    • Flora Zambesiaca
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • Flora of Somalia

    • Flora of Somalia
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • Flora of Tropical East Africa

    • Flora of Tropical East Africa
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • Herbarium Catalogue Specimens

  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0
  • Kew Bulletin

    • Kew Bulletin
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • Kew Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0
  • Lamiaceae Key Genus Fact Sheets

    • Nina Davies, Gemma Bramley and Don Kirkup, Royal Botanic Gardens, Kew
    • http://creativecommons.org/licenses/by/3.0
  • Trees of New Guinea

    • Trees of New Guinea
    • http://creativecommons.org/licenses/by-nc-sa/3.0