Part 61

The Alsodeia-group has regular or almost regular flowers. Gamopetalous corollas are found in Paypayroleæ. Sauvagesieæ differs the most by its regular corolla, and 5–∞ free or united staminodes.

250 species; especially in the Tropics.--The Ionidium-species are used as ipecacuanha. A number of Viola-species are cultivated as garden plants, especially V. odorata (sweet-scented Violet) and V. tricolor, which have a large number of varieties.

Order 6. =Frankeniaceæ.= A small order with doubtful relationships. Perennial herbs or shrubs; beach plants with nodose stem. Sepals united, petals free. Unilocular ovary, with 3–4 parietal placentæ. Fruit a capsule. Embryo straight, endospermous. Especially in S. Europe, Africa, on the shores of the Mediterranean and Atlantic.

Order 7. =Tamaricaceæ (Tamarisks).= To this order belong only Tamarix and Myricaria. They are shrubs of a cypress- or heather-like appearance, as the scattered leaves are very small, sessile, scale-like or linear, adpressed, entire, and usually glaucous, and the branches are slender and whip-like. The flowers are borne in small spikes or racemes, and are small, reddish or whitish, regular, ☿, hypogynous and polypetalous; formula S5, P5, A5 + 0 (Tamarix, which often has stipular teeth at the base of the filaments), or A5 + 5 (Myricaria, in which the stamens are united at the base); the number 4 may appear instead of 5, but in either case there is usually a tricarpellate gynœceum, which is unilocular and has either parietal placentæ (Myricaria) or a small basal placenta (Tamarix); 1 trifid style, or 3 styles. Capsule dehiscing along the dorsal suture, and resembling the Willows in having a unilocular ovary with numerous woolly seeds; but the seed-wool in this case is borne on the chalaza, and may be attached to a long stalk.--Some Tamarix-species shed part of their branches in the winter.--40 species; North Temperate, on the sea-shores or steppes, especially in Asia. Ornamental shrubs: Myricaria germanica, and Tamarix gallica.

Order 8. =Cistaceæ.= Shrubs or herbs, natives especially of the Mediterranean region. Flowers generally in raceme-like scorpioid cymes, regular, ☿, hypogynous; sepals 5, free, twisted in the bud, of which the two outer are generally much smaller than the others; petals 5, free, twisted in the bud (in the direction opposite to the sepals), fugacious; stamens numerous; gynœceum syncarpous, carpels usually 3–5, style simple, ovary unilocular, with parietal placentation (seldom divided into loculi, with axile placentation). The ovules are orthotropous in opposition to some of the other orders of this family. The capsule dehisces along the dorsal sutures; embyro curved. The leaves are simple, undivided, generally opposite and stipulate.--~They are Violaceæ with regular flowers, numerous stamens, and curved embryo. The numerous stamens are in reality only one or two 5-merous whorls, divided into a large number of stamens; these are formed, therefore, in descending order, like the lobes of many compound foliage-leaves.~

Helianthemum (Rock-Rose), has 3 carpels.--Cistus has 5 (-10) carpels.

About 70 species; temperate climates, especially about the Mediterranean. The resin of the Cistus-species has been used medicinally (ladanum).

Order 9. =Bixaceæ.= This order is closely allied to the Cistaceæ and Ternstrœmiaceæ; like these it has regular, 5-merous, hypogynous flowers with numerous stamens, unilocular ovary and parietal placentæ; sometimes unisexual flowers; it differs in having anatropous ovules, in the æstivation of the sepals, etc. All species (about 180) are trees or shrubs, with scattered, simple leaves, which usually have stipules, and are occasionally dotted with pellucid oil-glands.--Bixa orellana (Trop. Am.) is the best known species; it has a 2-valved capsule; the seeds are enclosed in a shiny red, fleshy testa, which contains the well-known orange or yellow dye, annatto.

Order 10. =Dilleniaceæ.= Gynœceum usually apocarpous, seed arillate. The flower has most frequently S5, P5, and compound stamens (one or more bundles); sometimes irregular. 200 species; Tropical; woody plants, many lianes.--Dillenia, Candollea, Pleurandra, Davilla, etc.

Order 11. =Elatinaceæ= (=Water-worts=). About 25 species belong to this order; especially in temperate climates. They are small, creeping, rooted, aquatic plants, with opposite or verticillate leaves and stipules. The flowers are solitary or situated in small dichasia in the leaf-axils, they are small, regular, ☿, hypogynous, with free petals, the same number in all 5 whorls (Sn, Pn, An + n, Gn), 3-merous (e.g. Elatine hexandra), 4-merous (e.g. E. hydropiper), or 5-merous (Bergia); the corolla-stamens are sometimes suppressed; petals imbricate without being twisted; the ovary is 3–4–5-locular, with 3–4–5 free styles; the capsule dehisces septicidally. The seeds are orthotropous or curved, often transversely ribbed, endosperm wanting. The order is most nearly allied to Hypericaceæ, whose primitive form it appears to represent.

Order 12. =Hypericaceæ= (=St. John’s-worts=). This order is recognised by its always opposite or verticillate, simple, and entire, penninerved leaves, without stipules, and usually dotted with pellucid glands; by the always ☿, regular, hypogynous flowers in a cymose inflorescence; the generally 5-merous calyx and corolla, with sepals and petals free; the stamens 3–5, numerously branched (Figs. 426, 427); and the gynœceum, 3–5-carpellate, styles usually free. The ovary is 3–5-locular, or unilocular with 3–5 parietal placentæ. Fruit a capsule (dehiscing septicidally) or berry. Endosperm absent.

The inflorescence is a dichasium or helicoid cyme. The structure of the flowers is the same as that of the foregoing orders: S5, P5; succeeding these in some cases are two 5-merous whorls of stamens in regular alternation, of which the inner is epipetalous; but the outer whorl is only represented by 5 small scales (Fig. 427), or is altogether absent (Hypericum calycinum, H. hircinum), and the inner divided into numerous stamens, that is, these 5 stamens are so deeply divided that 5 epipetalous groups bearing anthers are found (as in the Cistaceæ); in other cases the flower becomes 3-merous after the petals, stamens 3 + 3 following in regular alternation (Figs. 426, 427), the outer whorl of stamens in these cases is also present as staminodes (Fig. 427), or may be altogether suppressed. Carpels 3–5. The petals are often twisted in the bud, and are then oblique.

Hypericum. Some species have a square stem; in these cases the leaves are placed opposite the edges. Fruit a capsule.--Vismia has a berry.--~The flowers of Hypericum have no honey, and supply only pollen; self-pollination often takes place.~

About 240 species; the tropical ones being often shrubs or trees; the others generally perennial shrubs.--Hypericum, St. John’s-wort, contains a resinous, red matter, which can be extracted with alcohol. The American gamboge is the dried sap of species of Vismia.

Order 13. =Guttiferæ=, or =Clusiaceæ=. Closely allied to the Hypericaceæ and Ternstrœmiaceæ. Leaves opposite or verticillate. The flowers are often unisexual; stamens united; the gynœceum has most frequently a sessile, radiating or shield-like stigma.

370 species; chiefly in the Tropics (Am.). They are principally woody plants and their bark contains a yellow gum resin, “gamboge,” which is extracted from Garcinia morella (E. Ind.) and others. Mangosteen (Garcinia mangostana S.E. Asia), and Mammea americana (W. Ind.), have very delicious fruits. To this order also belong Platonia insignis, Pentadesma butyracea (the Butter-tree), Clusia, Calophyllum, Cataba, etc.

Order 14. =Ternstrœmiaceæ.= Trees and shrubs with scattered, simple, and often more or less leathery, evergreen, penninerved leaves, without stipules (Fig. 428). The two most important genera are: Camellia and the closely allied Thea (by some authorities these are united into one genus). The flowers are regular, hypogynous, and situated singly on very short stalks. A number of green floral-leaves are placed below the calyx and gradually pass over into the sepals, and the leaves (5–6) of the calyx again gradually pass over into the corolla (this being especially marked in Camellia), of which the number of leaves varies (5, 6, 7 and upwards); the calyx and the corolla are acyclic or eucyclic; the petals are slightly united at the base; stamens numerous in many whorls, the external ones are arranged in bundles and united with the petals as in the Columniferæ; gynœceum syncarpous; styles often free nearly to the base; ovary 3–5-locular, ovules numerous in each loculus. The fruit is a woody capsule.--~Other genera show more distinctly than these the same structure as in the preceding orders, namely: S5, P5, A5 + 5, of which the calyx-stamens are often suppressed, and the petal-stamens divided into numerous stamens.--Kielmeyera (S. Am.)~

260 species; especially in the Tropics (E. Asia, Am.) The leaves of Thea chinensis (or Camellia thea), the Tea-tree (E. Asia), are cultivated for the well-known “tea,” and contain theine: the best are the young, still hairy leaves, of greyish colour; there are many varieties. Ornamental plants, Camellia japonica and Actinidia.

Closely allied to this order are: Order 15. =Rhizoboleæ= (with enormously large hypocotyl--hence the name), and Order 16. =Marcgraviaceæ= (partly epiphytes, with dimorphic leaves and cup- or helmet-like, coloured, honey-secreting floral-leaves, which serve to attract insects).

Order 17. =Dipterocarpaceæ.= This order has taken its name from the large wings attached to the fruits in Dipterocarpus (the wings being largely developed sepals); trees and shrubs from Trop. Asia. 180 species. Camphor ready prepared is found in the stem of Dryobalanops camphora. Hopea; Vateria.

Family 12. =Gruinales.=

The flowers are hypogynous, ☿, polypetalous, usually regular (except Pelargonium, Tropæolaceæ, Balsaminaceæ) and throughout 5-merous: S5, P5, A5 + 5, or 5 + 0, G5 (epipetalous). The stamens soon fall off and are obdiplostemonous, often united at the base (monadelphous); the corolla-stamens are in some completely suppressed (e.g. Balsaminaceæ, Fig. 438), in others reduced to teeth (Linum, Fig. 431; Erodium). The Tropæolaceæ have 3 carpels and only 8 stamens (Fig. 437). Ring-like nectaries are not present, but at most only glandular bodies, borne outside the base of the stamens. Ovaries many-locular. The ovules as a rule are pendulous, with the micropyle directed outwards (Fig. 431, B), and the radicle therefore also points outwards. Usually herbs. Related to the Columniferæ.

Order 1. =Oxalidaceæ.= Most of the species are herbs with rhizomes; the leaves are stalked, compound, with entire leaflets which are folded and bent backwards in the bud (and in the sleep position), exstipulate; some species have sensitive leaves. The flowers (Fig. 429) are regular, and have S5, P5, which are twisted to the left or right in æstivation, A5 + 5, all united at the base (monadelphous), gynœceum 5-carpellate, styles 5 free, stigmas capitate, ovary 5-locular, ovules numerous. The fruit is a capsule opening with clefts on the dorsal sutures through which the seeds are ejected, while the fleshy, external layer of the testa springs off elastically. Embryo straight. Endosperm.

Oxalis (Wood-Sorrel). Leaves digitate. Species also occur with phyllodia, i.e. leaf-like petioles placed vertically without lamina; a few have pinnate leaves. The flowers are situated singly or in dichasia, and unipared scorpioid cymes. The pollination is effected by insects. Some species are trimorphic (long-, short-, medium-styled flowers) and some, e.g. O. acetosella, have cleistogamic flowers in addition to the ordinary ones. Glands are found on the outer side of the corolla-stamens or of all the stamens. O. tetraphylla and others have adventitious edible roots, resembling tap-roots.--Averrhoa is a tropical tree, with berries and pinnate leaves.

235 species (205 belong to Oxalis); chiefly in S. Africa and Trop. America.--Oxalate of potash is contained in the leaves of Oxalis.

Order 2. =Linaceæ.= Herbs with scattered or opposite, sessile, simple, small, entire leaves, without (rarely with small) stipules. The flowers (Fig. 430) are regular, 5- or 4-merous. Petals are free, twisted, quickly falling off. Stamens united at the base; the petal-stamens are either reduced to teeth (Fig. 431 A, m) or entirely suppressed. Styles free. The (5–4) epipetalous loculi of the ovary are incompletely halved by false divisional walls, each half contains one ovule (Fig. 431 C). The fruit is a spherical capsule, dehiscing along the divisional wall (Fig. 432); the 10 (-8) seeds have a straight embryo and very slight endosperm (Fig. 433).

Fig. 430.--The Flax plant.

Fig. 431.--A Flower after removal of sepals and petals; m petal-stamens reduced to teeth. B Longitudinal section of ovary. C Transverse section of capsule.