Connaraceae R.Br.

Connaraceae, E. J. Mendes. Flora Zambesiaca 2:2. 1966

Morphology General Habit

Erect or scandent shrubs, small trees or lianes, rarely rhizomatous shrublets

Morphology Leaves

Leaves alternate, imparipinnate or 1–3-foliolate, leaflets entire; stipules absent

Morphology Reproductive morphology Flowers

Flowers usually bisexual, actinomorphic or subzygomorphic; androecium and gynoecium usually dimorphic

Morphology Reproductive morphology Flowers Calyx

Sepals 5, imbricate or valvate, usually free

Morphology Reproductive morphology Flowers Corolla

Petals 5, free or slightly connate near the base, imbricate or rarely valvate

Morphology Reproductive morphology Flowers Androecium

Stamens 10 or 5, hypogynous to perigynous; filaments often united at the base; anthers 2-thecous, dorsifixed, with longitudinal introrse dehiscence

Morphology Reproductive morphology Flowers Nectaries

Disk absent or thin

Morphology Reproductive morphology Flowers Gynoecium

Carpels 5 or solitary, rarely 3, free, 1-locular; apparently all fertile but only 1–3 ripening into fruit; ovules 2, collateral, erect, attached at the base, near the base or near the middle of the ventral suture

Morphology Reproductive morphology Fruits

Fruit usually follicular, dehiscing by the ventral suture, sometimes indehiscent or dehiscing irregularly

Morphology Reproductive morphology Seeds

Seed usually 1 in each follicle, with or without endosperm, often arillate or pseudarillate

Connaraceae, J. H. Hemsley. Flora of Tropical East Africa. 1956

Morphology General Habit

Erect or scandent shrubs, small trees or lianes

Morphology Leaves

Leaves alternate, unifoliolate or imparipinnate; stipules and stipellae absent

Morphology Reproductive morphology Inflorescences

Inflorescence terminal or axillary, paniculate or racemose, often fascicled in axils of older leaves or on older branchlets

Morphology Reproductive morphology Flowers

Flowers hermaphrodite, rarely dioecious,1 actinomorphic, usually pentacyclic, androecium and gynoecium often dimorphic or heteromorphic

Morphology Reproductive morphology Flowers Calyx

Sepals 5, imbricate or valvate, usually free

Morphology Reproductive morphology Flowers Corolla

Petals 5, free or lightly connate near base

Morphology Reproductive morphology Flowers Androecium

Stamens 10, 5 episepalous longer than 5 epipetalous, the latter sometimes reduced and staminodal; filaments free or connate into a short tube at base; anthers dorsifixed, usually with longitudinal introrse dehiscence

Morphology Reproductive morphology Flowers Gynoecium

Carpels 5 or solitary, rarely 3, free; ovules normally 2, basal or attached to ventral suture, collateral, anatropous or orthotropous, erect. All carpels apparently fertile but usually only 1–3 mature

Morphology Reproductive morphology Fruits

Fruit usually follicular, dehiscence by ventral suture, sometimes indehiscent or dehiscence irregular

Morphology Reproductive morphology Seeds

Endosperm abundant, rudimentary or absent; cotyledons plano-convex, fleshy, or much flattened and small; radicle apical or laterally displaced Seed solitary, with ± fleshy aril covering part or all of the seed; aril free or sometimes fused with testa to form a compound fleshy pseudo-aril

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

Distribution

A pantropical family for which there is a large variation in genus circumscription and estimated number of species: between 12 and 24 genera and 110–300 species.

Recognition

Connaraceae have alternate, imparipinnate compound leaves with alternate leaflets, paniculate inflorescences, small flowers with 2 unequal whorls of stamens and fruits which are follicles with a single large seed, often with an aril-like sarcotesta. In New Guinea more species are climbers than trees or shrubs.

Morphology General Habit

Trees and climbers

Morphology General Indumentum

Indumentum when present of simple, rarely branched, hairs

Morphology Leaves Stipules

Stipules and stipels absent

Morphology Leaves

Leaves alternate, compound, imparipinnate or 3-foliolate, rarely 1-foliolate, petioles and petiolules present, both often pulvinate, leaflets usually alternate on the rachis, margin entire

Morphology Reproductive morphology Inflorescences

Inflorescences axillary or terminal, rarely cauliflorous, paniculate, often with bracteoles

Morphology Reproductive morphology Flowers

Flowers bisexual, actinomorphic, (4–)5-merous, pedicel usually articulated; calyx lobes free or fused at the base, sometimes accrescent in fruit; petals free; stamens 8–10, in 2 whorls, inner whorl often smaller or staminodal, anthers dorsifixed, dehiscing by lateral slits; ovary superior with 1–5 free carpels, 1–2 ovules per carpel, each carpel with a terminal style, plants usually heterostylus, stigmas capitate

Morphology Reproductive morphology Fruits

Fruits dry or fleshy follicles, dehiscing by a ventral, or sometimes dorsal, slit

Morphology Reproductive morphology Seeds

Seeds 1 per follicle, sarcotesta often present, fleshy, bright yellow or red, testa usually black.

Milliken, W., Klitgard, B. and Baracat, A. (2009 onwards), Neotropikey - Interactive key and information resources for flowering plants of the Neotropics. http://creativecommons.org/licenses/by/3.0

Morphology General Habit

Small trees, shrubs or lianas

Morphology Leaves Stipules

Stipules absent

Morphology Leaves

Leaves alternate, compound, imparipinnate, leaflets usually alternate on the rachis, margin entire or rarely revolute; blades sometimes with papillae present on abaxial surface (Pseudoconnarus Radlk., and some Rourea Aubl.); hairs unicellular (most species), dendroid (many Connarus L.), or sometimes glandular (Connarus)

Morphology Reproductive morphology Inflorescences

Inflorescences axillary, pseudoterminal or terminal, paniculate, racemose, or spicate

Morphology Reproductive morphology Flowers

Flowers actinomorphic, bisexual, usually 1 cm long, dark punctuations sometimes present (most Connarus) on petals, sepals, stamens and styles; sepals 5, distinct or partially fused, imbricate or valvate, often pubescent, persistent in fruit; petals 5 distinct, sometimes appearing fused just above the base, white, light yellow, or light pink, usually glabrous, sometimes pubescent (Connarus), the hairs sometimes glandular; androecium of 10 stamens, 5 long, episepalous, 5 short, epipetalous, the filaments glabrous, sometimes forming a tube at the base, sometimes glandular hairs present (Connarus), the anthers dorsifixed, glandular hairs sometimes present at top of connective (Connarus); gynoecium apocarpous, the ovaries superior, glabrous or pubescent, the carpels 1 (Connarus) or 5 (remaining genera), the styles 1 per carpel, the stigmas capitate or 2- lobed; ovules 2 per carpel but one aborting, nearly basal, collateral, orthotropous

Morphology Reproductive morphology Fruits

Fruits follicles, 1 (Cnestidium Planch., Connarus, Rourea) to several (Bernardinia Planch., Pseudoconnarus), often red at maturity, the persistent sepals covering the base, usually ascending or reflexed (Bernardinia and some Rourea)

Morphology Reproductive morphology Seeds

Seeds 1, black; aril bright red, yellow, white, or orange; endosperm abundant (Pseudoconnarus), poorly developed (Cnestidium) or absent.

Distribution

Bernardinia: monotypic, Pará to São Paulo, Brazil (endemic to tropical America). Cnestidium: two species, from México through Central America to Colombia, Venezuela, the Guianas, Ecuador and Cuba (endemic to tropical America). Connarus: 54 species, from Mexico to Southern Brazil (pantropical). Pseudoconnarus: five species, Colombia, Venezuela, Guyana, Suriname, Peru, and the states of Acre, Amazonas and Pará in Brazil (endemic to tropical America). Rourea: 48 species, from Mexico to Southern Brazil (pantropical). "All five genera are native. Three out of the five native genera are endemic to the Neotropics. Their geographic distribution within the region is given above under ""Distribution in the Neotropics""."

Diagnostic

Key differences from similar families: The lack of stipules is a key difference from the Leguminosae in sterile herbarium material. Dendroid and glandular hairs (several species of Connarus). Glandular punctuations on flower parts (most Connarus). Papillae on lower surface of leaflets (Pseudoconnarus, some species of Rourea). Two or more carpels maturing in Bernardinia and Pseudoconnarus, sometimes in Cnestidium, very rarely in Rourea. Distinguishing characters (always present): Compound, alternate, imparipinnate leaves without stipules. Flowers with 1 (Connarus) or 5 distinct carpels (remaining genera). Fruit a follicle. Seeds arillate. Notable genera and distinguishing features: Connarus can be distinguished from the other four American genera by the presence of one carpel only. This is the richest genus in terms of number of species in the Neotropics (54). Rourea is represented by 48 species. The areas of distribution of Rourea and Connarus overlap. Both Rourea (Roureainduta Planch.) and Connarus (Connarussuberosus Planch.) are important components of the Cerrado vegetation of central Brazil. Bernardinia stands out as being a monotypic genus that grows only in the eastern part of Brazil (states of Bahia, Minas Gerais, Rio de Janeiro, extending north to Pará and south to São Paulo). Pseudoconnarus can be easily distinguished by the trifoliolate leaves, always with papillae on the lower surface of the leaflets. Its distribution is restricted to northern South America. Cnestidium includes two species that are mutually exclusive geographically: C. guianensis grows in the Guianas and eastern Venezuela, while C. rufescens Planch. is known from Mexico to Colombia, western Venezuela, Ecuador and Cuba. Keys to genera of Neotropical Connaraceae Key based mainly on flowering material 1. Carpel solitary at flowering stage; petals with glandular punctuations — Connarus 1. Carpels 5 at flowering stage; petals without glandular punctuations ... 2 2. Sepals valvate or only narrowly imbricate; inflorescence (and fruit) densely pilose... Cnestidium 2. Sepals imbricate; inflorescence (and fruit) usually glabrous or villous but not densely pilose... 3 3. Ovary slightly stipitate; leaves consistently trifoliolate; leaflets papillose below... Pseudoconnarus 3. Ovary sessile; leaves uni-, tri- or multifoliolate; leaflets usually without papillae (when papillae present,   then leaflets more than five, i.e., Rourea spp.) ... 4 4. Flowers produced before or approximately at the same time as the leaves; fruiting calyx reflexed and more or less caduceus — Bernardinia4. Flowers produced after the leaves; fruiting calyx ascending, often accrescent, rarely reflexed — Rourea Key based mainly on fruiting material 1. Follicle usually solitary at maturity ... 21. Follicles several at maturity ... 4 2. Fruiting calyx usually accrescent —Rourea 2. Fruiting calyx not accrescent... 3 3. Endosperm absent; sepals imbricate — Connarus3. Endosperm present but scanty; sepals valvate or only narrowly imbricate — Cnestidium 4. Endosperm copious; leaves trifoliolate, the leaflets papillose below; flowers produced after the leaves —Pseudoconnarus 4. Endosperm absent; leaves imparipinnate, the leaflets lacking papillae below; flowers produced before or approximately at the same time as the leaves ... Bernardinia

Note

The Connaraceae were placed in the Rosales by Cronquist (1981) and in the Connarales by Takhtajan (1987). The APG (2003) placed the family in the Oxalidales, next to the Oxalidaceae, Brunelliaceae, Cephalotaceae, Cunoniaceae, and Elaeocarpaceae. The family is pantropical and includes 16 genera and about 300-350 species. Its center of distribution is Western Africa. In the Neotropics there are 5 genera and 110 species. While most species are found mostly within the tropics of Cancer and Capricorn, two taxa extend past 27° S in the state of Santa Catarina, Brazil: Connarusrostratus (Vell.) L.B.Sm. and Roureagracilis G.Schellenb. Notes on delimitation: The delimitation of the family has not been questioned. Number of genera: Five genera: Bernardinia Cnestidium Connarus Pseudoconnarus Rourea