NYCTAGINACEAE the Four-o'clock Family(to Genus key)
Family characters: Annual, biennial, or perennial herbs, usually from a woody or fleshy taproot, some (but not ours) shrubs or trees. Stems variously procumbent to scandent or erect, commonly dichotomously or trichotomously branched, glabrous to pubescent, often with swollen nodes; producing betalain pigments and not anthocyanins. Leaves opposite, simple, petiolate to sessile, estipulate. Flowers generally perfect or sometimes functionally unisexual and the plants dioecious; flowers regular sometimes dimorphic or heterostylous, usually arranged in corymbose or panicoid cymes, sometimes solitary, racemose, spicate, capitate, or umbellate; inflorescence often subtended by an involucre of free or united bracts, these herbaceous or petalloid, often persistent and accrescent in fruit; sometimes the inflorescence reduced to a single flower and giving the appearance of one large flower with calyx-like bracts and a petalloid calyx. Calyx petalloid, of (3)5(8) fused sepals, tubular to funnelform or campanulate, plicate to valvate in bud, deciduous or persistent, the base often becoming hardened and enclosing the fruit (in some genera, e.g. Mirabilis, with 1-flowered inflorescences, the result is a flower with calyx-like bracts below the fruit and a corolla-like calyx above); true corolla none. Stamens (1) as many as the calyx lobes or sometimes as many as 30, hypogynous, filiform, unequal, often connate basally. Gynoecium included in the corolla tube but superior (appearing inferior in species where the calyx base hardens around the ovary), unicarpellate and unilocular; style 1, elongate, slender, stigma commonly capitate to peltate, ovule 1, nectary disk sometimes present around the ovary. Fruit an achene or nut, often enclosed by the hard or leathery calyx base and termed an anthocarp, fruits often clustered in the involucre. Seed often with starchy perisperm.
About 350 species in 45 genera in warm and tropical regions, especially in the Americas, a few in temperate regions. There are 13 genera and 69 species in TX; 3 genera and 8 species in our area, including 1 endangered species.
Most members of the Nyctaginaceae are not economically important. A few have medicinal or food value. Some, notably Mirabilis (Four-o'clock) and Bougainvillea, are cultivated for ornament.
1. ABRONIA Juss. Sand Verbena
Annual or perennial herbs; stems prostrate to erect, branched; sometimes clumped and seemingly acaulescent; pubescent, often viscid. Leaves petiolate, opposite, the two of a pair often of different sizes, blades succulent, entire to sinuate. Flowering stems sometimes scapose; flowers perfect, few to many in long-pedunculate heads subtended by 5 conspicuous, scarious, usually distinct bracts; perianth funnelform to salverform, tube elongate, slender, and commonly constricted above the ovary; limb 5-lobed, often withering and persisting. Stamens usually 5, included. Ovary ovoid, style filiform and stigma linear or fusiform, included. Fruit turbinate to biturbinate, deeply 2- to 5-lobed or -winged, leathery, hardened, or papery. Embryo with one cotyledon aborted.
About 36 species of N. Amer; 5 species in TX (2 listed in Correll and Johnston since transferred to Tripterocalyx); 2 species here, one endangered.
Some species, especially A. fragrans, are cultivated as ornamentals.
2. A. ameliae Lundell Amelia's Sand Verbena. Coarse perennial herb; stems to 60 cm high or long, spreading, thick viscid-glandular pubescent and villous with hairs of variable length; somewhat grooved when dry. Petioles 1 to 8.5 cm long, those of the lower leaves longer than the blades; blades ovate to elliptic or orbicular, 3 to 8 cm long, 2 to 6 cm broad, apices rounded, bases subcordate to subtruncate, decurrent at the base, margins noticeably sinuate, fleshy, leaves drying stiff and brittle, sparsely short viscid-pubescent above and below. Peduncles 2.5 to 13 cm long, slender, viscid-puberulent. Floral bracts 5 to 7, thin, oblong to elliptic or obovate, 10 to 16 mm long, 5 to 10 mm broad, apex broadly rounded and acute, greenish to pale magenta, externally viscid-villous. Heads many-flowered, to 5 cm broad; flowers with perianths orchid/pale magenta, 18 to 25 mm long, villous-viscid, tube slender, limb to 1 cm broad, 5-lobed, the lobes emarginate. Stamens 5, included. Anthocarp narrowly turbinate, apex rounded to truncate, not narrowed, attenuate at the base, 7 to 9 mm long, 3 to 4.5 mm broad, 5-winged, reticulate-veined, glabrous to sparsely pubescent at the apex. Seeds oblong-oblanceolate, ca. 2.5 mm long. Sandy areas along roadsides in post oak belts. Rio Grande Plains to the Panhandle, reported as far E. as Leon Co.; endemic. Mar.-Jun.
2. BOERHAVIA L. Spiderling
Annual or perennial herbs; stems sprawling or trailing, branched, sometimes diffuse, radiating from a central crown, variously pubescent or glandular, internodes often villous. Leaves opposite, the two of each pair unequal, usually paler beneath, entire to sinuate, often acute. Flowers to 1.5 cm broad, perfect, not in involucres but each flower bracted, in cymose panicles or racemes, pedicels jointed just below the ovary. Calyx corolla-like, campanulate to nearly rotate, constricted above the ovary, limb deciduous, shallowly 5-lobed. Stamens 1 to 5, exserted or inclined, filaments of different lengths, connate below. Ovary stipitate, style filiform and stigma peltate. Anthocarp ovoid or obpyramidal, with 3 to 5 angles or, less commonly, 5 to 10 ribs, rarely with 3 to 5 wings, glabrous to pubescent. Seed with a curved embryo. Boerhavia is Linnaeus' original spelling, but the name Boerhaavia appears in many works.
About 40 species, primarily tropical and subtropical; 11 in TX with the inclusion of formerly-separate Commicarpus scandens (L.) Standl. as B. scandens L. Two species are found in our area.
A few are used in medicines or as food, but not ours. Some are weedy.
1. B. diffusa L. Scarlet Spiderling. Perennial from a fleshy or woody, sometimes stout root; stems few to many, decumbent, procumbent, or ascending, sparingly branched below, 2 to 15 dm long, brown or herbaceous; lower portions minutely puberulent to viscid- pubescent, especially near the nodes; upper portions densely glandular-puberulent to somewhat viscid or even glabrate. Petioles 3 to 40 mm long, commonly villous; blades thin or rarely leathery, suborbicular or widely ovate to ovate-oblong, 1.5 to 5.5 cm long, 8 to 50 mm broad, bases subcordate to rounded or truncate, apices rounded to acute, margins entire to sinuate, paler beneath, brown-punctate or not, glabrous to minutely puberulent, margins villous-ciliate; lower surface with veins sparsely villous, sometimes the entire leaf densely hirsute or hirtellous. Flowers in lax, much-branched terminal and axillary cymes, branches divergent or ascending and glabrous to puberulent or glandular. Involucres absent. Flowers sessile to short-pedicelled, in clusters of 2 to 4 at the ends of slender peduncles 3 to 10 mm long. Floral bracts minute, less than 2 mm long, deciduous or persistent, ovate or lanceolate, viscid-puberulent. Perianths purple-red to red-green, limb 2 mm broad, all minutely glandular-puberulent; stamens 1 to 3, briefly exserted. Anthocarp narrowly obovoid, rounded at the apex, 2.5 to 4 mm long, densely glandular-puberulent (or glandular-pilose), 5-ribbed or -angled, angles and grooves smooth. Waste places, fencerows, riverbanks, fields, etc. S. and W. TX; W. FL to TX, and SE. CA; Mex. through Cen. Amer. to N. and W. S. Amer., also W.I. and Caribbean; adventive elsewhere, including once in NC. July-Nov. [B. coccinea Mill., B. caribaea Jacq.].
2. B. erecta L. Erect Spiderling. Taprooted annual or perennial; stems erect to decumbent, usually branched at the base, 2 to 12 dm long or tall, branches spreading or decumbent, sometimes red-tinged; lower portions finely pubescent, middle internodes often with viscid brown bands; upper portions glabrous or minutely puberulent. Petioles 4 to 40 mm long, ca. 1/2 the length of the blades; blades ovate-rhombic or ovate-deltoid, or the upper ovate-lanceolate to linear, 2 to 8 cm long, 1.4 to 5 cm broad, apices acute or obtuse to rounded, apiculate; bases truncate to rounded or somewhat cuneate; margins entire to undulate or repand; both surfaces usually brown-punctate, glabrescent, lower surface paler than upper (or glaucous.) Inflorescences axillary and terminal, cymose, umbellate, or somewhat racemose, usually well-branched, branches filiform, erect to ascending, usually glabrous but sometimes viscid. Involucre absent. Flowers in clusters of 2 to 6 on slender peduncles, pedicels 1 to 5 mm long. Floral bracts linear to lanceolate, reddish, 0.6 to 1.2 mm long, persistent. Perianths white or tinged with pink to purple, 1 to 1.5 mm long, tube glabrous or glandular-punctate, limb campanulate, sparsely pubescent. Stamens 2 or 3, exserted. Anthocarp green or yellow-green, primarily glabrous, narrowly obpyramidal, 3 to 4 mm long, 1 to 1.5 mm broad, apex truncate, 5- angled, the angles obtuse to acute, smooth, the grooves between coarsely cross-rugose. Dry fields, banks, waste places, and in cultivated ground. SC and FL W. to TX, AR, and S. AZ, S. through Mex. and Cen. Amer. to N. S. Amer., also W.I. and Caribbean. Spring to fall.
3. MIRABILIS L. Four-o'clock
..Perennial herbs, usually from large tuberous roots; stems erect to ascending or sprawling, simple or branched from the base, branches forking, nodes often swollen; foliage glabrous to pubescent, glandular, or hispid. Leaves opposite, often fleshy, sessile to petiolate, variously-shaped, glabrous to pubescent or glaucous. Involucres terminal or axillary or both, in loose or congested cymose arrangements or involucres solitary in the axils. Involucres each with 1 to 10 flowers, 5-lobed, lobes equal or unequal, calyx-like, green or tinged with red or purple, more or less campanulate, in some species accrescent and papery in fruit, usually becoming rotate and noticeably veined. Flowers perfect, regular, calyx colored and corolla-like, tube elongate and constricted above the ovary, limb expanded, campanulate to salverform or funnelform, 5-lobed, deciduous in fruit but the perianth base persisting and becoming hardened around the ovary. True corolla absent. Stamens 3 to 6 (sometimes more), unequal, filiform, united at the base, anthers exserted. Ovary superior, unicarpellate, style filiform and stigma capitate. fruit a 1-seeded anthocarp (ovary enclosed by the leathery remnants of the calyx), 5-angled or 5-ribbed, surfaces smooth to tubercled, glabrous to pubescent. Seed filling the pericarp, pericarp fused to the testa; endosperm mealy.
..About 45 to 60 species of warm parts of the Americas, especially SW. N. Amer.; 29 species listed for TX; 4 from our area. Positive identification often requires mature fruits, and those species from section Oxybaphus form a complex group without clear specific circumscriptions.
..Some, notably M. jalapa, are grown for ornament; a few are used for dyes or in cosmetics or medicines. The tuberous roots of some are edible.
Perennial from a large, tuberous or fleshy root. Stems erect or sometimes somewhat floppy, 4 to 10 dm tall, well-branched, branches erect to ascending, stout or slender, nodes commonly swollen. Foliage dark green, glabrous to slightly pubescent (rarely short-villous), often viscid, but not glandular. Petioles slender, ca. 1/2 as long as the blades, 0.3 to 5 cm long, reduced upwards and the uppermost leaves nearly sessile. Leaf blades ovate, ovate-deltoid, or rhombic to rhombic-elliptic, 4 to 14 cm long, 2 to 8.5 cm broad, bases truncate to subcordate, apices acuminate, glabrous or rarely pubescent. Peduncles 1 to 2 cm long, arranged cymosely at the ends of the branches, inflorescence with many reduced leaves. Involucres green, campanulate or turbinate, 7 to 15 mm long, lobes linear-lanceolate to ovate-lanceolate, acute, usually ciliolate and bristle-tipped, as long as the tube or up to twice as long; involucre glabrous or short-pubescent to villous, enlarged only slightly in fruit and remaining herbaceous. Flower 1 per involucre, perianth salverform to trumpet-shaped, 2 to 6 cm long, deep red-purple to white (in cultivated forms also rose, yellow, and variegated), glabrous to lightly villous externally; tube ca. 2.5 mm thick and gradually expanded upward, limb 2 to 3.5 cm broad, spreading, shallowly 5-lobed, notched, or sometimes (especially in cultivated material) nearly entire. Stamens 5, equalling the perianth or slightly exserted. Anthocarp ovoid or obovoid, dark brown to black, 7 to 10 mm long, 5-angled, wrinkled-warty, warty, or rugose, glabrous to puberulent (sometimes described as resembling a miniature hand- grenade.) Plains, prairies, roadsides; often escaped from cultivation in W. TX, sometimes persistent where established. Native to tropical America, now found throughout Mex., Cen. Amer., and S. Amer. Spring or summer until frost.
..Widely cultivated for the colorful flowers and often strongly night-scented. The common name refers to the plants' habit of blooming at dusk; flowers last one day. In cultivated strains the flowers are sometimes much larger and the perianth occasionally has extra lobes or stamens (up to about 10); some of these plants are up to 2 m tall. Used by some cultures in medicines. The flowers are used as a food dye in Chin and the seed in cosmetics in Japan.
2. M. nyctaginea (Michx.) MacM. Wild Four-o'clock. (to Mirabilis species key)
Perennial from a thick fleshy taproot, crown usually branched; stems several to many, erect to ascending, 3 to 15 dm tall, branched below or above, branches divaricate and forking or sometimes simple, glabrous to pubescent or glaucous, sometimes ridged and/or purplish, nodes usually swollen. Uppermost leave sessile but lower leaves with petioles 1 to 10 cm long. Blades ovate- or deltoid-lanceolate to ovate-oblong or cordate, (3)5 to 12(15) cm long, to ca. 5 cm broad, base truncate, rounded, or cordate; apex acute to obtuse or acuminate, glabrous or pubescent (ours apparently tending toward pubescent.) Peduncles 3 to 10 mm long, pubescent, arranged in umbels in forked terminal clusters (sometimes appearing paniculate); involucres 5 to 6 mm long at anthesis, (8)10 to 15(17) mm long in fruit, membranous, persistent, widely campanulate to almost rotate, lobes 5, obtuse or obtuse-apiculate, united nearly 2/3 their length, margins pilose, sometimes pilose externally or near the base, commonly somewhat reddish and veiny in fruit. Flowers regular and perfect, 3 to 5 per involucre, perianth pink to purple or rarely white, campanulate, tube short (to 2 mm long at anthesis), limb (8)10 to 15(18) mm broad. Stamens 3 to 5, exserted. Anthocarp grayish or brown to nearly black, 4 to 6 mm long, cylindric-ovoid or narrowly elliptical, pilose, warty, or rugose, with 5 ribs and 5 angles. Seeds pale brown, 3 to 3.5 mm long, obovoid. Roadsides, weedy areas, calcareous gravels of the Post Oak Belt and West Cross Timbers; Man. and WI, W. to MT, S. to TN, TX, and NM; also Mex.; adventive in the E. U.S. and CA. Spring-summer; ours mostly April and October. [Oxybaphus nyctagineus (Michx.) Sweet, Allionia nyctaginea Michx., A. ovata Pursh].
3. M. albida (Walt.) Heimerl White Four-o'clock. (to Mirabilis species key)
Perennial from an often woody taproot and a short, branched rootstock. Stems 1 to few, erect to ascending, 2 to 12 dm tall, simple or branched, 4-angled below, nodes swollen, internodes below the inflorescence each with 2 long bands of short (less than 0.5 mm) incurved hairs or else bands of hairs absent and the stems nearly glabrous, often whitish. Leaves sessile or with pubescent petioles to 5(10) mm long. Blades variable in shape, linear-lanceolate to oblong-or elliptic-lanceolate or ovate, 3 to 12 cm long, 3 to 30 mm broad, roughly 3 to 12 times longer than wide; thin or thick and succulent, base cuneate or attenuate, apex acute to short-acuminate, rounded or blunt; margins entire to subsinuate, with or without cilia, surfaces glabrous to pilose, upper surface bright green, lower surface often glaucous or whitened. Inflorescence in young plants of solitary pedunculate involucres; in older plants involucres in much-branched cymose-paniculate arrangements; branches of inflorescence and peduncles puberulent with short, incurved hairs or short-viscid pubescent or both; inflorescence with many reduced, bract-like leaves. Involucres with slender peduncles, 1- to 3-flowered, campanulate, 3.8 to 4 mm long at anthesis, persistent and enlarging to (8)10 to 12(15) mm long in fruit, 5-lobed, lobes acute to rounded, united about 2/3 their length, glabrous to sparsely or densely viscid-pilose. Perianth rose, pink, or whitish, (6)8 to 10 mm long, lobes shorter than the tube, glabrous to sparsely (short-) pilose. Stamens 3 to 5, exserted, style exserted. Anthocarp dark olive-brown, 5 to 6 mm long, obovoid, broadly angled, angles with cylindrical or flattened tubercles, each tubercle topped with a tuft of silvery hairs, faces also tuberculate. Seed obovoid, yellow-brown, ca. 3.5 mm long. Dry soils of meadows, roadsides, fencerows, waste places, and so on. Most of TX except the Panhandle; SC and TN, N. to Man., W. to ND, KS, MO, LA, and TX. May-Nov. [includes var. lata Shinners and var. uniflora Heimerl; Allionia bracteata Rydb., A. albida Walt., Oxybaphus albidus (Walt.) Sweet; some authors include also M. decumbens (Nutt.) Daniels = A. decumbens Nutt.].
..See note at M. linearis, below.
4. M. linearis (Pursh) Heimerl Narrowleaf Four-o'clock. (to Mirabilis species key)
Perennial from a deep, elongated, woody taproot, rootstock branched. Stems erect to ascending or procumbent, simple or branched near the base and often branched above, 2 to 10 dm tall, usually glaucous, often whitish; lower portions glabrous to puberulent, upper portions viscid-puberulent or short-villous, especially in the inflorescence. Leaves sparse or numerous, sometimes crowded, linear to narrowly linear-lanceolate, sessile or attenuate to a short petiole, 3 to 10 cm long, 1 to 5 mm wide, generally about 15 to 30 times longer than wide, apex acute or obtuse, entire to (rarely) undulate or sparsely dentate, thickish, generally gray-green above, glaucous usually at least beneath, glabrous to viscid-puberulent. Inflorescences sometimes axillary, more commonly paniculate or cymose-paniculate. Involucres rotate-campanulate, 3.8 to 4.2 mm long at anthesis, persistent and enlarging to (6)8 to 10(12) mm long in fruit, lobes acute to rounded, glandular-pubescent or viscid-villous. Flowers usually 3 per involucre, perianth purplish-red to pink or nearly white, pilose, 8 to 12 mm long, limb deeply 5-lobed, lobes retuse or emarginate. Stamens exserted. Anthocarp brownish-olive, 4 to 5 mm long, obovoid, 5-angled, the angles obtuse, densely pubescent to sparsely strigose, not tuberculate, sides transversely rugose. Seeds yellow-brown, 2.8 to 3.2 mm long, rounded-obovoid. Dray areas, especially on calcareous or igneous soils, also sandy plains. Common in the Panhandle, SE. to Hunt, Jack, Nueces, and Kleberg Cos. MN and SD to MT, S. to MO, TX, and AZ; adventive elsewhere. Spring-summer. [M. angustifolia (Nutt.) MacM., Allionia linearis Pursh, Oxybaphus linearis (Pursh) Robins; some authors also include M. diffusa (Heller) Reed = Allionia diffusa Heller].
NOTE: The differences between M. albida and M. linearis, at least in our area, are subjective. Specimens can not be distinguished by leaf shape or pubescence, and even fruit morphology can be inconclusive. Most specimens from our area identified as M. linearis have tuberculate fruits and are probably M. albida. Others have fruits with elongate, transverse tubercles intermediate between the cylindrical tubercles of M. albida and the transverse wrinkles of M. linearis. It is possible that the true M. linearis is not present in our area. R. W. Spellenberg, who has done work with the genus, describes the Oxybaphus section of Mirabilis (which includes these two species) as confused, consisting of entities which have diversified but not fully speciated. A thorough sorting out of this section is a daunting task no one wants to attempt.
Last updated by HDW . on 3 February 1995