Rubiaceae in Flora of Pakistan @ efloras.org

Rubiaceae

S. NAZIMUDDIN AND M. QAISER

Department of Botany, University of Karachi, Karachi-75270

Rubia cordifolia
Illustration
Credit: M. Rafiq

Trees, shrubs, climbers, erect, prostrate or procumbent annual-perennial herbs. Stems cylindrical or quadrangular, unarmed or rarely spiny-prickly. Raphides often present. Leaves opposite or less often verticillate, decussate, simple, mostly entire very rarely toothed. Stipules inter- or intmpetiolar, mostly persistent, distinct, free, or connate and sheathing, sometimes leaf-like, and forming whorls of 4-10 foliar stipules which am sometimes smaller than true leaves, scale-like or filiform, forming glandular setae. Inflorescence various, mainly different forms of dichasial cymes, thyrsoid, spike or head, corymbose, paniculate or solitary. Bracts present or absent. Flowers usually bisexual, rarely unisexual, usually actinomorphic, very rarely zygomorphic or ± bilabiate, 4-6-merous. Calyx 4-5 (or more)-lobed; tube mostly adnate to the ovary, limb (3-) 4-5 (-8)-lobed or toothed, sometimes only minutely so, with valvate, imbricate or contorted aestivation becoming enlarged after anthesis and persistent in fruit. Corolla 4-5 (-10)-lobed, gamopetalous, infundibuliform, campanulate or rotate, lobes twisted, valvate-induplicate or rarely imbricate in bud. Homostylous or heterostylous with 2 or rarely 3 forms. Stamens generally equalling and alternating with the corolla lobes, epipetalous; anthers 2-celled, introrse, usually distinct, dehiscing longitudinally. Disc mostly present, annular or cushion shaped. Ovary inferior, rarely sub-inferior-superior, generally 2-loculed, rarely 3-5 or more loculed. Ovules solitary-numerous in each locule; placentation exile or apparently basal (rarely parietal in Gardenia). Style simple or branched, stigmas linear, filiform or capitate or bilobed. Fruit a loculicidal or septicidal capsule, berry or a drupe, or of 2 dehiscent or indehiscent cocci or mericarps; rarely syncarps (Nauclea & Morinda), 1-many seeded. Seeds rarely winged, the endosperm entire or ruminate, usually copious and fleshy or cartilaginous, absent in Guettardeae.

A large family of c. 500 genera and c. 6000 species. Predominantly woody and distributed in the tropics and sub-tropics. Represented in Pakistan by 33 genera and c. 87 species, about half cultivated or introduced for ornamental purposes. Cultivated taxa have been marked with an asterisk (*). Native genera are mostly herbaceous in our area.

Acknowledgements: We are grateful to the Directors/Curators of the following herbaria for the loan of herbarium material: ISL, K. PESH, PPFI-B. Thanks are also due to Dr. B. Verdcourt, Mrs. D. M. Bridson of Royal Botanic Gardens, Kew, Mr. I.C. Hedge of Royal Botanic Garden, Edinburgh, Prof. F. Ehrendorfer and Dr. E. Schonbeck-Temesy of Botanisches Institut and Botanischer Garten der Universitat, Wien, Austria for going through the manuscript and offering very valuable suggestions. We are also indebted to Dr. H.W. Lack and Dr. M. Hakki, Botanischer Garten and Botanisches Museum, Berlin for providing photocopies of relevant literature. The financial assistance provided by the United States Department of Agriculture under P.L. 480 with the coordination of Pakistan Agricultural Research Council, Islamabad is gratefully acknowledged.

1 Plants armed with thorns or spines (2)

+ Plants unarmed (4)

2 (1) Flowers 4-merous [cultivated] 22 Catesbaea

+ Flowers 5-merous [wild] (3)

3 (2) Calyx lobes foliaceous, persistent. Fruit 25-38 mm in diameter 25 Catunaregam

+ Calyx lobes neither foliaceous nor persistent. Emit 6-8 mm in diameter 24 Himalrandia

4 (1) Inflorescence a globose head (5)

+ Inflorescence not a globose head (8)

5 (4) Annual or perennial herbs. Flowers tetramerous. Fruit crowned with persistent calyx 16 Borreria

+ Shrubs or trees, rarely climbers. Flowers pentamerous. Fruit not crowned with persistent calyx (6)

6 (5) Corolla lobes imbricate, throat glabrous. Fruit an aggregate of capsules, few to many seeded. Seeds embedded in fleshy receptacle 30 Neolamarkia

+ Corolla lobes valvate, throat hairy. Fruit not as above (7)

7 (6) Shrubs or small trees. Calyx lobes nearly connate. Fruit a compound succulent berry. Seeds not winged 21 Morinda

+ Trees. Calyx lobes free. Fruit not as above. Seeds winged 29 Mitragyna

8 (4) Nodes with whorl of 4-8 (-10) leaves and leaf l ike stipules. Herbs and herbaceous climbers. Fruits globose. Plants often adhesive due to prickles or harsh hairs (9)

+ Nodes with opposite leaves, rarely in whorls of 3-5 but plants either shrubs or trees (13)

9 (8) Flowers in dense spikes 8 Crucianella

+ Flowers in panicles, cymes or capitula (10)

10 (9) Most flowers enclosed by a large membranous white bract 10 Callipeltis

+ Flowers not enclosed by the membranous bracts (11)

11 (10) Fruit fleshy, berry l ike 9 Rubia

+ Fruit dry (12)

12 (11) Ultimate inflorescence branches with bracts and often bracteoles. Corolla with a very conspicuous tube 7 Asperula

+ Ultimate inflorescence branches without bracts or bracteoles. Corolla with a very short tube 11 Galium

13 (8) Some calyx lobes in each inflorescence dilated into a large white or coloured lamina in fruit 28 Mussaenda

+ No calyx lobe dilated into large lamina in fruit (14)

14 (13) Each pair of leaves with one large and one small leaf (anisophyllous). Anthers connivent 2 Argostemma

+ Leaves not anisophyllous. Anthem not connivent (15)

15 (14) Fruit fleshy, drupaceous or a berry (16)

+ Emit dry, capsule or mericarp (20)

16 (15) Ovary 5-loculed. Placentation axile 1 Hamelia

+ Ovary 1-2-loculed. Placentation basal or parietal (17)

17 (16) Ovules numerous. Pollen in tetrads 23 Gardenia

+ Ovules 1-2. Pollen not in tetrads (18)

18 (17) Plants foetid. Corolla tube funnel-shaped, lobes valvale in bud 15 Serissa

+ Plants not foetid. Corolla tube salver-shaped, lobes twisted in bud (19)

19 (18) Bracts coriaceous, not sheathing. Style not twice as long as corolla tube, stigmatic lobes divergent. Leaves without bacterial nodules [cultivated] 26 Ixora

+ Bracts membranous, lower bracts sheathing. Style twice as long as corolla tube, stigma fusiform. Leaves with bacterial nodules [wild] 27 Pavetta

20 (15) Ovary 5-loculed, style ending in 5 stigmatic branches (21)

+ Ovary 2-3 loculed, style either simple or 2-lobed (rarely 3-lobed in Rondeletia) or ending in 2 stigmatic branches (22)

21 (20) Capsule 5-valved at the base. Bracteoles united forming a tubular involucre 12 Leptodermis

+ Capsule 5-valved at the apex. Bracteoles free 13 Spermadictyon

22 (20) Ovules many in each locule. Fruit many-seeded (23)

+ Ovules 1-2 in each locule. Fruit 1-few-seeded (30)

23 (22) Large shrubs or trees (24)

+ Herbs or shrubs (27)

24 (23) Flowers usually di-or trimorphic. Stipitate glands usually present between each pair of calyx lobes. Capsule beaked. Seeds without wings 6 Pentas

+ Flowers monomorphic. Glands absent. Capsule not beaked. Seeds winged (25)

25 (24) Flowers small. Corolla lobes valvate in bud. Stigma clavate to capilate 32 Hymenodictyon

+ Flowers often large. Corolla lobes imbricate in bud. Stigma not so (26)

26 (25) Flowers small, 0.5 cm long. Anthers exserted [wild] 33 Wendlandia

+ Flowers 3-5 cm long. Anthers included [cultivated] 31 Rondeletia

27 (23) Leaf blades usually narrow and uninerved or lateral nerves obscure. Flowers small, usually tetramerous, monomorphic (only in flora area, elsewhere many species dimorphic). Stipitate glands absent between each pair of calyx lobes [wild] (28)

+ Leaf blades usually broad with obvious lateral and tertiary venation. Flowers large, pentamerous, di-or timorphic. Stipitate glands usually present between each pair of calyx lobes [cultivated] 6 Pentas

28 (27) Calyx teeth contiguous on the capsule. Capsule splitting longitudinally 3 Hedyotis

+ Calyx teeth distant on the capsule. Capsule splitting at the apex (29)

29 (28) Corolla tube cylindrical. Anthers and stigma included, stigmas always below the anthers 5 Kohautia

+ Corolla tube cylindrical or infundibuliform, if cylindrical than either anthers and stigmas exserted or anthers below the stigma 4 Oldenlandia

30 (22) Erect or prostrate annual or perennial herbs Corolla 4-lobed. Stamens 4 (31)

+ Subshrub to shrubs. Corolla 5-lobed. Stamens 5 (32)

31 (30) Calyx tube ovoid, globose, limb usually absent or inconspicuous. Fruit didymous not crowned 7 Asperula

+ Calyx tube ovate, limb 2-4-lobed, well developed. Fruit not didymous, crowned by persistent calyx 16 Borreria

32 (30) Stipules free and scarious. Fruit didymous, not encircled by persistent calyx teeth 14 Aitchisonia

+ Stipules connate with petiole forming a sheath with 2-many setae. Fruit not didymous (33)

33 (32) Calyx limb accrescent after anthesis (34)

+ Calyx limb not accrescent after anthesis (35)

34 (33) Calyx limb salverform, enlarged in fruit to form large orbicular and horizontal 5-lobed membranous reticulately veined wings. Bracts similar to stipules 20 Pseudogaillonia

+ Calyx limb bifid, enlarged in fruit to form 2 erect wings. Floral bracts forming an obconical 6-8-toothed membranous sheath 19 Pterogaillonia

35 (33) Bracts heteromorphic, forming denticulate sixpartite involucre or sheath 17 Jaubertia

+ Bracts homomorphic not forming a sheath or involucre 18 Gaillonia

List of lower taxa