Part 79

This family is closely allied to the Rubiales through the Valerianaceæ, which have almost the same structure as many of the Caprifoliaceæ. It attains the highest development in the Dipsacaceæ, which are composite plants, but differs from Compositæ in the position of the ovule, etc.

Order 1. =Valerianaceæ.= Herbaceous plants or under-shrubs with opposite leaves, often pinnate; stipules absent. The flowers are borne in dichasia and in scorpioid cymose inflorescences and are entirely without any plane of symmetry (Fig. 593). The calyx and corolla are 5-merous, but the calyx is frequently very insignificant and ultimately a pappus, as in Compositæ; the corolla is frequently saccate or produced into a spur at the base. Most frequently, only 3 (4–1) of the 5 stamens are developed; these are free. Carpels =3=, which form an inferior ovary, often with 3 loculi, but only 1 of the loculi contains =1= pendulous, anatropous ovule (Figs. 593, 594 A), the other loculi are empty and shrink up more or less completely. (Compare Fig. 593 A, B). Style 1, stigma tripartite. Endosperm absent; embryo straight, with the radicle directed upwards.

The inflorescences are dichasia, or unipared scorpioid cymes with the branches developed in the axil of the second bracteole. Both the bracteoles are generally present and frequently form 4 very regular, longitudinal rows on the branches of the inflorescence.--5 stamens do not occur (except perhaps in Patrinia). The suppression of stamens and carpels takes place most readily on the anterior side of the flower and that turned towards the first bracteole (a) (Fig. 593), whose branch is suppressed in the dichasium; after this the posterior median stamen is next suppressed.

By the vegetative characters as well as by the inflorescence and the flower, the order is allied to the Caprifoliaceæ and especially to the Sambuceæ.

In the least modified (oldest) forms, Patrinia and Nardostachys, there is an almost regular flower, a 5-merous calyx, 4 stamens, and 3 loculi in the ovary, 2 of which however are barren. The stamens in Valerianella are reduced to 3, in Fedia to 2 (posterior), and the calyx is less distinctly 5-dentate; the 2 empty loculi in the ovary are still visible. Fedia has a small spur at the base of the corolla. Valeriana has a very reduced, hair-like calyx (pappus), an unsymmetrical, salver-shaped corolla with a sac-like, nectariferous spur at the base, 3 stamens and only 1 loculus in the ovary (Figs. 594, 593). Centranthus (Fig. 593) is still further reduced. The corolla has a spur and only 1 stamen; ~unipared scorpioid cymes with 4 rows of bracteoles. In the last two genera there is a peculiar wall in the corolla-tube, which divides it longitudinally into two compartments (indicated by a dotted line in Fig. 593), one of which encloses the style. This wall is low in Valeriana, but in Centranthus it reaches as far as the throat.--The rays of the pappus are pinnately branched and rolled up before the ripening of the fruit. 12–20 in number (Fig. 594 A, B).~

Val. officinalis and others are protandrous: in the first period the stamens project from the centre of the flower (Fig. 595 a), the stigmas in the second (b) when the stamens have become bent backwards. (V. dioica is diœcious with large ♂-and small ♀-flowers).--275 species; especially from the temperate and colder parts of the northern hemisphere of the Old World, Western North America and the Andes.--Bitter properties are characteristic, such for instance as the volatile acid and volatile oil of Valeriana; these occur especially in the rhizomes. OFFICINAL; the rhizomes of V. officinalis.--The true Indian “Nardus,” an important medicine and perfume in India, is extracted from Nardostachys (Himalaya). A variety of Valerianella olitoria is sometimes used as salad.

Order 2. =Dipsacaceæ= (=Teasels=). Herbs with opposite leaves without stipules. The flowers are situated in compact capitula each with an involucre. A characteristic feature of the order is that each flower of the capitulum has a gamophyllous “epicalyx” (Figs. 597, 599, 600), which envelopes the inferior ovary. The flowers (Figs. 599, 600) are ☿, 5-merous (S5, P5, stamens typically 5, G=2=), but the calyx often expands at the edge into a membrane with 5, or an indefinite number of bristles or teeth (pappus, Figs. 597, 600), and the zygomorphic, funnel-shaped corolla is sometimes 5-lobed and bilabiate (2/3), but most frequently 4-partite (Fig. 599), the two lobes of the upper lip coalescing into one lobe, as in certain Labiatæ, Veronica and Plantago; the æstivation is imbricate.

FIG. 598.--Inflorescence (the flowers in a zone below the apex commence to flower first).

FIG. 599.--Flower (4/1).

FIG. 600.--The same in longitudinal section.]

The stamens are never more than 4, the posterior one remaining undeveloped; they usually have free anthers which generally project considerably (Fig. 599). The ovary is unilocular with 1 pendulous ovule and bears 1 undivided style; fruit a nut with 1 seed, containing endosperm and with the radicle turned upwards (Fig. 597).

The flowers do not always open in centripetal order, a fact which may be observed especially in the Dipsacaceæ, in which a zone of flowers round the centre of the capitulum opens first, and the flowering then proceeds both upwards and downwards (Fig. 598). This has probably some connection with the fact that the capitulum has arisen from the coalescence of several dichasial inflorescences. In species of Scabiosa the flowers open simultaneously at the circumference, or in a zone at the centre.--The morphological explanation of the “epicalyx” is not quite certain; in all probability it is formed from two united bracteoles, for an “epicalyx” is distinctly formed in this way in one of the Valerianaceæ, Phyllactis.--The ray-flowers are larger and more irregular, labiate or ligulate, than the disc-flowers, yet not in so high a degree as in the Compositæ.

=A.= A scarious bract to each flower. Scabiosa has a 5-lobed corolla; the “epicalyx” has a dry, scarious, often finally large collar, and the true calyx is formed of long bristles (generally 5) (Fig. 597). Succisa pratensis (Devil’s-bit) has a 4-lobed corolla, the collar of the “epicalyx” is herbaceous; the calyx as in the preceding.--Pterocephalus.--Dipsacus (Teasel); large, spiny and stiff-haired herbs with capitula, or short, thick spikes on which both the involucral-leaves and bracts project considerably, and are stiff and spinose (Fig. 598). The “epicalyx” has short teeth, or is almost entire. ~The leaves of the stem unite together in pairs, so that shallow cups are formed round the stems in which rain-water may collect.--Cephalaria.--Morina: the flowers are falsely verticillate as in the Labiatæ; the calyx has 2 laterally-placed, entire, or emarginate lobes; 2 stamens, or 2 large and 2 small ones.~

=B.= Bristles, but no true bract to each flower. Knautia; the corolla is 4-partite, the calyx cup-like, with many bristles or teeth on the edge.

POLLINATION is in many species effected by insects. The honey is secreted by a ring round the base of the style. The flowers in our native species are considerably protandrous. Gynodiœcious flowers also occur.--150 species; especially in the Mediterranean and the Orient; the order is not represented in the South Sea Islands, Australia and America.--The heads of the true Teasel (Dips. fullonum) are used for carding wool, on account of the elastic bracts, which are hooked at the point. The order has bitter properties; tanin, etc.; but no species are used in medicine or the household.--Scabiosa atropurpurea, etc., are used as ornamental plants.

Order 3. =Calyceraceæ.= This order resembles the Compositæ in the valvate æstivation of the corolla and the more or less united stamens, and the Dipsacaceæ in the undivided style, pendulous ovule and endosperm. The calyx is frequently composed of 5 distinct scales. An “epicalyx” is wanting.--20 species; America.

Family 35. =Campanulinæ.=

The flower is epigynous, perfect, with 5 sepals, 5 petals, and 5 stamens in regular alternation, and =3= (2–5) carpels. The sepals in all cases are distinct, but narrow and pointed, so that the æstivation is open. The corolla is gamopetalous with (as in the Compositæ) valvate, or slightly infolded-valvate æstivation. The stamens are nearly always situated on the torus without being united to the corolla (Figs. 601, 604). The anthers adhere or unite and form a tube with introrse anthers from which the pollen is swept out by the projecting, brush-like hairs on the style (as in the Compositæ). The ovary is =3=-(2–5) locular, many ovules in each loculus. The fruit is generally a many-seeded capsule (or berry). Embryo in the centre of a fleshy endosperm.--The majority are herbs with scattered leaves, without stipules. The presence of latex and inulin, together with the tubular formation of the anthers, the pollination, etc., indicate a relationship with the Compositæ.

The Cucurbitaceæ are by some authorities placed in this family as being most closely related to the Campanulaceæ. Although the corolla is most frequently gamopetalous, and other similarities to the Campanulaceæ are present, yet on account of the structure of the ovule, and for other reasons, the Cucurbitaceæ are here placed in the Choripetalæ. The Campanulinæ without doubt proceed upwards to the Compositæ, with which, in addition to the occurrence of inulin and laticiferous vessels (Cichorieæ), there are many corresponding features both in the structural and biological relations (epigyny, valvate æstivation of the corolla, tendency of the anthers to adhere or unite, protandry with a stylar-brush, etc.) The inflorescence of Jasione is almost identical with that of the Compositæ.

Order 1. =Campanulaceæ= (=Campanulas=). The flowers are regular and in some only semi-epigynous, 5-merous, except in the gynœceum which is 3-merous (the unpaired, median carpel being generally posterior), more rarely 2–5-merous, and has a corresponding number of stigmas and loculi in the ovary; the placentation is axile with a large number of ovules. The median sepal is posterior. The stamens frequently have broad, free bases (Fig. 601 H) which cover the nectariferous upper surface of the ovary; the anthers only fit loosely together, and become separated as soon, as the pollen is shed (Fig. 601 G), 1 long style, which is studded by sweeping-hairs (stylar-brush), which ultimately become invaginated; the stigmas do not unfold until the stamens have shed the pollen (Fig. 601 E, G). Fruit a capsule.--Herbs, more rarely under-shrubs or shrubs, with latex and scattered, undivided leaves without stipules. The inflorescence is most frequently a raceme or spike with terminal flower.

=A.= Capsule opening at the side by pores and small valves: Campanula (Canterbury-bell); the corolla is bell-shaped, rarely almost rotate; capsule obconical. ~The pores of the capsule are found near the top of the fruit when it is erect, and near the base when it is pendulous, so that the seeds are not liberated unless the capsule is forcibly shaken, and they are thus ejected to a considerable distance.~--Phyteuma (Rampion) has free petals, which for a long time adhere at the apex and form a tube round the stamens (Fig. 601); inflorescence compact, spike-like or capitate, in the latter case resembling that of the Compositæ, and frequently with an involucre similar to the one possessed by this order. ~Specularia (rotate corolla, prismatic capsule), Michauxia (flower 8-merous).--Symphyandra has syngenesious anthers.~

=B.= Capsule with valves at the apex, loculicidal dehiscence: Jasione; the petals are almost free. The anthers are united at the base (syngenesious). The flowers are situated in capitate umbels with involucres.--Wahlenbergia; Platycodon.

=C.= Berry: Canarina; flower, 6-merous; leaves opposite.

Protandry is general (Fig. 601). 510 species; principally in temperate countries. Several genera furnish ornamental plants, but are of little use for other purposes. The roots of some Campanula-and Phyteuma-species are large and may serve as pot-herbs (C. rapunculus, P. spicatum).

Order 2. =Cyphiaceæ.= In this order the corolla is zygomorphic and the stamens free, hence it is intermediate between orders 1 and 3.--About 24 species; Africa.

Order 3. =Lobeliaceæ= (=Lobelias=). This order may briefly be described as Campanulaceæ with zygomorphic flowers and anthers united into a tube, in most cases slightly bent; generally 2 carpels and an inverted position of the flower, i.e. the median sepal is turned anteriorly (Fig. 602) (a position which is found to occur within the Campanulaceæ). A twisting of the peduncle takes place even before flowering (as in the Orchids) so that the ordinary position of the 5-merous Dicotyledons appears to be restored. The zygomorphy of the flower is especially present in the corolla, which has a bipartite under-lip and a tripartite upper-lip, and is, in Lobelia, anteriorly (apparently posteriorly) deeply cleft (Fig. 602). There is 1 style, but the stigma is capitate and bilobed and surrounded at its base by a whorl of hairs, which assists in pollination (as a stylar-brush) in the same manner as the sweeping-hairs in the Campanulaceæ and Compositæ. There is no terminal flower in the spicate, or racemose inflorescences.--Lobelia has a capsule, several others have berries. ~Isotoma (regular flower); Heterotoma has a spur; Siphocampylos; Lysipoma (pyxidium); Clintonia (1–locular fruit). Metzleria (all the petals are free).~

FIG. 603. Flower (2/1).

FIG. 604.--Longitudinal section of the same.]