Taxa treated:
H. nummularium
ssp. nummularium
ssp. obscurum
ssp. pyrenaicum
H. oelandicum
var. canescens
var. oelandicum
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Cistaceae Taxa treated:
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 © Flora Nordica

by Björn Widén
(6b, 20080221)

Sorry, HTML-manus inte klart!

This treatment is partly outdated - the final version will appear in print.

1 Annual, with basal rosette; stigma sessile
- Perennial, without basal rosette; style present
2 Leaves all opposite and decussate, oblong to linear; stamens all fertile; flowers in raceme-like cymes
- Upper leaves alternate, linear; outer stamens sterile; flowers solitary
2. Fumana

1. Helianthemum Mill.

Miller, Gard. Dict. abr. ed. 4 (1754).
Rhodax Spach (1836).
Literature. Du Rietz 1923.
Chamaephytes. Evergreen, woody dwarf-shrubs. Leaves short-petiolate, opposite, oblong to lanceolate; stipules present or absent.
Inflorescences raceme-like, scorpioid cymes with small linear bracts; flowers fully open in sunshine, closed at night and in cold weather. Sepals markedly unequal, the three inner ones ovate, the two outer ones smaller, linear. Petals 5, caducous. Stamens numerous, all fertile, ± erect, on tactile stimulation spreading close to the corolla. Style sigmoid at base or straight. Capsule ovoid, loculicidal, 3-valved.
Chromosome base-number x=10 or 11; diploids in Norden.
Taxonomy. The two species native to Norden differ in morphological, cytological and embryological traits and are referred to separate subgenera. A separation of subgenus Plectolobum (H. oelandicum and related species) at the generic level as Rhodax Spach has been generally accepted in SE Europe, but was not supported by Arrington & Kubitzki (2003).
Both native species belong to complexes with variation centra in southern and central Europe. Taxonomists have laid much weight on the presence or absence of stellate hairs on the lower surface of the leaves (Proctor & Heywood 1968). Variation in stellate hairs of H. nummularium shows a distinct geographical pattern in Norden, while the variation in H. oelandicum is more intricate. Trichome production has been shown to be a character with simple inheritance in several studies of plants (Kärkkäinen & Ågren 2002). Preliminary results indicate that inheritance of stellate hairs on the lower surface of the leaves depends on one or very few genes in both species of Helianthemum (Widén, personal observation).

1 Leaves with stipules; flowers 2-3 cm diam.
- Leaves without stipules; flowers 1-1.5 cm diam.

1. Helianthemum nummularium (L.) Mill.      Map

Miller, Gard. dict. ed. 8, no. 12 (1768). – Cistus nummularius L., Sp. pl.: 527 (1753). – Type: Linnaean herbarium 889.54 (LINN) lectotype, sel. by López, An. Jard. Bot. Madrid 50: 46 (1992)..
H. nummularium subsp. arcticum (Grosser) Hiitonen (1933).
D Soløje. F kultapäivännouto.solrose. S solvända.
Stem short, vertical, just above the ground producing numerous procumbent to ascending, up to 25 cm long shoots. Leaf blades elliptic-oblong to lanceolate, on flowering shoots 10–30 × 3–10 mm (2–5 times as long as wide), on non-flowering shoots smaller and 2–3 times as long as wide, slightly revolute at the margin; upper surface subglabrous to hairy with bristles, lower surface subglabrous (rarely) or covered with a thin to dense whitish felt of stellate hairs and usually with bristles. Stipules narrowly lanceolate, 3–8 mm, as long as or longer than the petiole.
Inflorescences with up to 10–15 flowers. Pedicels 5–11 mm. Inner sepals 5–9 mm. Petals 8–16 × 7–15 mm, pure yellow, often with a dark orange spot at the base, very rarely entirely orange. Stamens 50–100, 4–6 mm. Style 3.5–4.5 mm, ± straight; stigma entire, with short papillae. Ovary whitish tomentose. Capsule 5–7 mm, nodding at dehiscence because the pedicel becomes arched. Seeds up to 30, brown, rounded to weakly polyedric, 1.3–1.7 mm, covered by a mucilaginous sheath, when dry tuberculate and when wet forming a viscous sheath. – Early summer to mid-summer.
2n=20 (S Sk 4). – [2n=20]
Distribution. Nem–SBor. – Indigenous in large parts of its Nordic area; declining. D fairly common in Sjæ, elsewhere scattered: NJy at and south of Limfjorden, ØJy Glatved, Klejs Skov, Mariager Fjord, VJy Mønsted, Daugbjerg, Hesselvig, Skovbjerg, LFM Gedser and Møns Klint, and western Brn. N Øf Moss. S distinctly southeastern: very common in Öl and Gtl; common in Bl, Klm, eastern SmI, Ög (except the northernmost part), eastern Srm and most of Upl; fairly rare in southern and eastern Sk and part of eastern Vg; rare in southeasternmost Vsm; BhG Romelanda, possibly also Strömstad; Gst Gävle and Valbo, Hls Norrala (Andviken, known since 1924) and Mpd Sundsvall (Norra Stadsberget, originally sown but established in south-facing cliffs, known from 1910 to at least 1972); formerly also in Hl Hasslöv (c. 1754) and Östra Karup (before 1924), Dlr Rättvik (before 1831) and possibly Husby (before 1842). F indigenous and fairly common in A; archaeophytic in parts of V and EH (see subsp. obscurum); PeP Tornio 1961 (polemochorous, intermediate between the subspecies); probably casual in ES Valkeala 1948 (railway); see also under the subspecies (partly uncertain records from St, U, EH and ES). 
Europe, Turkey, the Caucasus, N Iran.
Habitat. Dry to moderately dry, sunny sites with low vegetation, usually on basic or neutral substrate (sand, moraine or bedrock with a thin soil layer); commonest in seminatural, usually grazed grassland but also present e.g. in woodland fringes and in herb-rich, south-facing cliffs. The species is favoured by moderate grazing but becomes damaged by too intense grazing. It stands the initial phases of overgrowth but disappears in later phases. – Throughout Norden declining due to artificial fertilization and overgrowth.
Biology. The roots form mycorrhiza (Boursnell 1950). Horizontal shoots sometimes root, giving rise to restricted vegetative propagation. Old shoots eventually die back and become replaced by new shoots from the base. Flowering shoots develop mainly from apical buds on the previous year’s shoot and flower in late May and June; during favourable conditions inflorescences are formed also on shoots of the current year so that flowering may continue until late summer. The flowers are usually open one at a time, taking a position at the top of the inflorescence; when the petals are fully expanded the stamens are exposed to pollen-collecting insects. The flowers are homogamous with stigma and anthers functional at about the same time. The species has been reported to be ± self-compatible (Proctor 1956), but isolated plants do not set seed in cultivation (Widén, personal observation).
Variation. The Helianthemum nummularium complex shows great diversity, especially in mountain areas of southern and central Europe, and was subdivided into eight subspecies by Proctor and Heywood (1968); the Nordic plants cover the range of variation of their subsp. nummularium and subsp. obscurum.
In the Nordic area, pubescence on the lower surface of the leaves varies ± continuously from subglabrous with few or no stellate hairs to a dense whitish felt of stellate hairs, but the extremes are much more common and are often recognized as separate taxa: subsp. obscurum with few or no stellate hairs, and subsp. nummularium, with a whitish felt of stellate hairs. The frequency of the two morphs and intermediates between them varies geographically in Norden. Subsp. obscurum is the exclusive or dominating morph in populations in D, while the two morphs usually (but not always) occur together in populations in the southwestern part of the distribution area in S. Subsp. nummularium is, however, the only morph in most of S Klm and Ög, in Öl, Gtl, Vg and further north. Intermediates between subsp. obscurum and subsp. nummularium have a sparse cover of stellate hairs on the lower side of the leaves. These stellate hairs are usually larger than stellate hairs in subsp. nummularium. Intermediates are found in mixed populations as well as in populations with exclusively subsp. obscurum, especially in D. Offspring of individual plants in mixed populations segregates for pubescence in cultivation (Widén, personal observation). Individuals of subsp. obscurum or intermediates between the two morphs can rarely be found in populations of var. nummularium even outside the main distribution of subsp. obscurum.
Populations consisting of a mixture of subsp. obscurum, subsp. nummularium and intermediates occur in other parts of Europe as well (Azzouzi et al. 1997). Intermediates are similar to experimentally produced F1 hybrids between the two subspecies (Widén, personal observation).
Variation between populations in size of leaves and flowers is not correlated with variation in pubescence. There is a weak geographical trend in variation of leaf shape across the overlapping distribution area of the two hair morphs in Norden (leaves being more oblong in D and more lanceolate in S Klm).
There is some variation in petal colour. The orange spot at the base of the petal is rarely large, covering a large part of the petal; in Öl, one specimen with homogeneously orange petals has been found; pale yellow or whitish petals occur very rarely. – Subsp. pyrenaicum (from southwestern Europe; in Norden a casual garden escape) has pink petals.

1A. subsp. nummularium      Map

D Filtet Soløje. F ketopäivännouto. S ljus solvända.
Lower surface of leaves with a dense whitish felt of stellate hairs (older leaves and leaves on flowering shoots sometimes more sparsely hairy). Petals pure yellow, often with a dark orange spot at the base, very rarely entirely orange.
Distribution. D rare and declining: NJy Gedsted; Sjæ Hørsholm (relic of cultivation?), Jægerspris, Næsbystrand, Røsnæs, Solrød, Tornved, Tømmerup, LFM Gedser, Brn the western coast at Hellig Peder and Hammershus. N Østfold Moss (Jeløy). S the dominating or exclusive morph throughout except in Sk, where it is rare throughout the area of the species, and in Bl, where it is common in the easternmost part but rare in the west. F indigenous and fairly common in A; archaeophytic in V along ancient traffic routes in the southwest archipelago (surviving in Dragsfjärd and Korppoo; older and partly perhaps unreliable records from Kustavi, Salo, Turku and Vihti) and in EH Janakkala (Hakoinen fort hill and its surroundings); EH records of uncertain status from Hausjärvi and (only pupil specimens) Hauho and Iitti; apparently a casual recent incomer in U Hanko 1934 (roadside), ES Lappeenranta 1932 (pupil specimen) and Kouvola 1945 (railway). Reported as indigenous from U Vantaa 1940 but possibly planted (dry lawn beneath calcareous rock); repeatedly searched for in vain in the 1990’s. EH records of uncertain status from Hausjärvi and (only pupil specimens) Hauho, Iitti and Kangasala); apparently a casual recent incomer in U Hanko 1934 (roadside) and Nurmijärvi 1974 (yard lawn), ES Lappeenranta 1932 (pupil specimen), Kouvola 1945 (railway) and Valkeala 1948 (railway) and PeP Tornio 1961; an apparently well-established population in EP Vaasa (possibly polemochorous, first record 1951) persisted to the late 1950’s. Reported as indigenous from U Vantaa 1940 but possibly planted (dry lawn beneath calcareous rock); repeatedly searched for in vain in the 1990’s.
S and C Europe, extending to the British Isles, the Baltic states, S Russia and Turkey.

1B. subsp. obscurum (Čelak.) Holub      Map

Holub, Acta Horti Bot. Prag. 1963: 53 (1964). – H. chamaecistus subsp. obscurum Čelak. (1875). – Described from Bohemia.
H. ovatum (Viv.) Dunal (1824). – H. nummularium subsp. ovatum (Viv.) Schinz & Thell. (1909).
H. chamaecistus ssp. hirsutum (Mérat) Vollm. (1914)
Cistus helianthemum L. (1753). H. vulgare Gaertn. (1788).
H. chamaecistus Mill. (1768).
D Bakke-Soløje. F tanskanpäivännouto. S mörk solvända.
Lower surface of the leaves glabrous, with few stellate hairs on the midrib only, or with sparse stellate hairs all over. Stellate hairs often larger than in var. nummularium. Petals pure yellow, often with a dark orange spot at the base.
2n=20 (S Sk 2).
Distribution. D declining; fairly common in Sjæ; scattered in western Brn and in NJy at and south of Limfjorden; ØJy Glatved, Klejs Skov and scattered at Mariager Fjord. VJy Mønsted, Daugbjerg, Hesselvig and Skovbjerg. LFM Møns Klint. S fairly common in Sk (except in the northwest), Bl (except the easternmost part), southeastern SmI and southwesternmost Klm (Kråksmåla, Madesjö, Örsjö, Torsås and Vissefjärda); fairly rare in northern SmI from Bringetofta north to Säby; Ög Västra Tollstad; Gtl Fardhem 1908, Västerhejde 1892; perhaps casual in Klm Kalmar 1884. F EP Vaasa (possibly a wartime incomer; the population apparently well-established when first recorded 1951, persisting to the late 1950’s); apparently a casual recent incomer in U Nurmijärvi 1974 (yard lawn); uncertain records (pupil specimens) from St Loimaa and EH Kangasala.
Europe except the British Isles, the southern Iberian Peninsula and the southern Balcan; Turkey, the Caucasus and N Iran.
1C. subsp. pyrenaicum (Janchen) Schinz & Thell. 1925 (H. nummularium var. roseum (Willk.) López Gónzales). S röd solvända. - Similar to subsp. nummularium but with pink petals.
Sjæ Halskov 1994 (escaped from cultivation). S Sk Malmö (docks) 1990. - The Pyrenees and neighbouring mountains. - Map (not in the book).

2. Helianthemum oelandicum (L.) Dum. Cours.         Ill.

Dumont de Courset, Bot. cult. 3: 129 (1802). – Cistus oelandicus L., Sp. pl.: 526 (1753). – Type: Öl, Linnaean herbarium 689: 40 (LINN), lectotype sel. by López, An. Bot. Jard. Madrid 50: 51 (1992).
D Ølands-Soløje. öölanninpäivännouto. ölandssolvända.
Dwarf shrub. Main stem vertical, 2–10 cm; branches ± horizontally spreading, 5–15 cm. Leaves without stipules; petiole 2–7 mm; blade ± lanceolate to oblong, 7–25 × 2–7 mm (2–5 times as long as wide), upper surface glabrous or with few to many bristles, lower surface glabrous to densely stellate-tomentose; leaves (as well as inflorescences and sepals) with minute glandular hairs, especially on otherwise glabrous plants.
Inflorescences with (1–)3(–10) flowers, glabrous to densely covered with bristles and stellate hairs. Pedicels 5–10 mm. Inner sepals 2.5–4.5 mm. Petals 5–8 × 4–7 mm, often slightly crenulate at apex, reflexed when the flowers are fully open, pure yellow without an orange spot. Stamens 30–60, 2–4 mm. Style sigmoid at base; stigma 3-lobed, with long papillae. Ovary glabrous to whitish tomentose. Capsule 4–5 mm, erect when ripe. Seeds (1–)3–5(–15), light brown, ovoid to polyedric, smooth, 1.3–1.7 mm. – Early summer to early autumn (flowering peaks in early June and July–August).[2n=22]
Distribution. Nem–SBor. – S Öl very common in the south (Stora Alvaret), more scattered in the north (owing to scarcity of habitat).
The species occurs in the British Isles, S and C Europe, N Africa, Turkey and the Caucasus. In Norden it is represented by the endemic subsp. oelandicum.
Habitat. Dry, open, ± well-drained habitats on limestone pavement and calcareous grassland on alvar ground; often dominant.
Biology. Roots without root hairs, probably with mycorrhiza. Horizontal shoots rarely rooting. The flowering intensity varies between years depending on degree of dying back of branches during drought. Mainly wind-pollinated; the flowers are rarely visited by pollen-collecting insects (mostly in wind-protected habitas). The flowers are homogamous and ± self-incompatible (Widén 1986). The seeds germinate during a prolonged period with a peak in spring and may remain viable in the soil seed bank for 3–4 years.
Variation. Helianthemum oelandicum subsp. oelandicum is extremely variable in hairiness of leaves, inflorescences and sepals. This variation is maintained in cultivation and is geographically structured in Öland. The frequency of different hair-morphs varies significantly between populations and seems to be correlated with environmental factors such as drought in summer and waterlogging and frost-induced movements in the soil during winter and early spring. In areas where both morphs occur, hairy plants tend to be more frequent in dry, well-drained habitats, while glabrous plants are more frequent in habitats subjected to waterlogging (Widén 1988). Very rarely, individuals with pale yellow or whitish petals can be found.
There is also variation in flowering phenology (fig.). The most common morph (var. oelandicum) produces inflorescences only on the previous year’s growth and flowers during a few weeks in early June. Var. canescens produces some inflorescences on the previous year’s growth, but most inflorescences are on the current year’s growth; the flowering period is therefore longer, with one peak in early June (on the previous year’s growth) and a second, larger one in July–August (mainly on the current year’s growth). The concentrated flowering of var. oelandicum is more efficient in wind-pollination than the prolonged flowering of var. canescens. Thus, var. oelandicum has often a higher fruit and seed set than var. canescens. On the other hand, seed production in var. oelandicum is often reduced by drought in spring and early summer, while seed production in var. canescens is often favoured by late summer rain.
The two varieties have allopatric distributions; they occur sympatrically only in a narrow zone (from tens to a few hundred metres) of overlap. In this zone var. canescens usually occurs in well-drained habitats on bedrock with a thin layer of weathered soil, var. oelandicum in less well-drained habitats with a thicker layer of weathered soil.
No barriers against cross-fertilization exist, but the allopatric distribution and the partial separation of flowering times restrict gene flow between the two morphs. Introgression can be traced in flowering phenology. Experimentally produced F1 hybrids have most inflorescences on the previous year’s growth, and the few inflorescences on the current year’s growth often have a delayed flowering compared with the main summer flowering of var. canescens.
Var. canescens has traditionally been referred to H. canum, while var. oelandicum was referred to a group of taxa without stellate hairs on the lower side of the leaves (H. alpestre, H. italicum and H. rupifragum). However, crossing experiments show that all morphs in Öland are closely related to each other and that they are closely related to the H. canum group (Widén 1986). Consequently, many modern floras treat the complex as one species, H. oelandicum, with a number of geographical subspecies (Castroviejo et al. 1993, Stace 1997).

2a. var. oelandicum     Map     Ill.

D Almindelig Ølands-Soløje. F kaljuöölanninpäivännouto. N ölandssolrose. äkta ölandssolvända.
Leaves, inflorescences and sepals glabrous, with glandular hairs and/or bristles, and rarely also with a thin felt of stellate hairs. Inflorescences mainly at the apex of the previous year’s growth, during favourable conditions also laterally on the previous year’s growth; number of internodes (3–)5–15(–20). – From late May to mid-June (flowering lasts only 2–3(–4) weeks). A few scattered flowering plants can be found very occasionally in the autumn, especially in wet years.
2n=22 (S Öl 10).
Distribution. S Öl Stora Alvaret except the southernmost part (to south of the village Albrunna in Södra Möckleby and south of the village Södra Sebberneby in Ventlinge); also in small alvar areas in the northern and middle parts of the island.
Habitat. Well-drained to occasionally waterlogged open limestone gravel, especially along fissures in the limestone pavement; sometimes in more closed calcareous grassland.
Variation. The frequency of hairy plants differs significantly between populations (Widén 1988). Glabrous plants dominate in most small alvars in northern Öland (Sterner 1936) and in a large area in the eastern part of Stora Alvaret (northwest of the village Segerstad), but are rare in some parts in the west (Widén 1988).

2b. var. canescens (Hartm.) Fr.     Map     Ill.

Fries, Nov. Fl. suec. 7: 115 (1823). – Cistus ölandicus β [unranked] canescens Hartm., Handb. Skand. fl.: 207 (1820). – H. canum subsp. canescens (Hartm.) Á. Löve & D. Löve (1961). – Type: ***
H. canum auct., non (L.) Baumg. (1816).
H. italicum (L.) Pers. (1806) subsp. rupifragum sensu Sterner (1936), non (A. Kern.) Hayek (1925).
D Grå Ølands-Soløje. villaöölanninpäivännouto. filtsolrose. sen ölandssolvända.
Leaves, inflorescences and sepals with bristles and stellate hairs, the lower surface of the leaves with or without a whitish felt of stellate hairs. Inflorescences mainly laterally on the current year’s growth, some also laterally on the previous year’s growth; number of internodes in inflorescences on the current year’s growth (1–)2–3(–8), in those on the previous year’s growth (2–)5–8(–12). – From late May to August, and more sparsely throughout autumn.
2n=22 (S Öl 5).
Distribution. S Öl the central parts of southernmost Stora Alvaret (± south of a line between the limestone quarry north of the village Albrunna in Södra Möckleby and the village Löt in Gräsgård); also in a ± isolated alvar north of the village Eketorp in Gräsgård, and in small alvar areas south of Stora Alvaret.
Habitat. The main occurrences in Stora Alvaret are on drained limestone pavement and limestone gravel; in the southern part of Stora Alvaret usually in less frost-disturbed sites than var. oelandicum.
Variation. The proportion of inflorescences on the previous year’s growth and on the current year’s growth varies between years and between populations, and especially the flowering intensity in June varies between years (Widén 1980). The most densely hairy plants dominate in a small area in the northern part of the area of var. canescens but are less common elsewhere. They are rare in the small alvars south of Stora Alvaret. Plants without a whitish felt of stellate hairs on the lower side of the leaves have been mistaken for a taxon from SE Europe (H. italicum subsp. rupifragum; Sterner 1936). However, shape and size of leaves and petals differ significantly between var. canescens and this southeast european taxon, whereas no clear differences can be found between hair morhs of var. canescens (Widén, unpublished). Furthermore, preliminary results from crossing experiments within var. canescens show a clear segregation in two morphs, with and without a whitish felt of stellate hairs on the lower side of the leaves, respectively, in F2. This indicates that pubescence is a trait with simple inheritance and that variation in stellate hairs should be treated taxonomically at a low taxonomical level only.

Rare casual

Helianthemum ledifolium (L.) Mill. 1768. – Annual, 10–50 cm; variable in pubescence. Leaves lanceolate to elliptic-obovate, 10–40 mm. Stipules linear-lanceolate, to half as long as the leaves. Pedicels erect, shorter than the sepals. Petals yellow, shorter than the sepals. – [2n=20]
D Sjæ Hastrup at Køge 1982 (garden weed). – S Europe. The Danish specimen belongs to subsp. lasiocarpum (Jacques & Hérincq) Nyman 1878. – Map (not in the book).

2. Fumana (Dunal) Spach

Spach, Ann. Sci. Nat. Bot. Ser. 2, 6: 359 (1836). – Helianthemum sect. Fumana Dunal in DC., Prodr. 1: 274 (1824).

Fumana procumbens (Dunal) Gren. & Godr.     Map

Grenier & Godron, Fl. France 1: 173 (1847). – Helianthemum procumbens Dunal in DC., Prodr. Syst. 1: 275 (1824). – Described from “Gallia austr., Italia, Tauria”.
Cistus fumana L. (1753). – Helianthemum fumana (L.) Mill. (1768). – Fumana vulgaris Spach, nom. illeg. (1836)
Gotlandssoløje. rentopäivänkilo. gotlandssolrose. S gotlandssolvända.
Chamaephyte. Dwarf-shrub with short, thick, vertical stem and prostrate, up to 25 cm long branches. Stems with minute, arched, multicellular glandular hairs, thereby appearing greyish; leaves, pedicels and sepals with similar, but more sparse hairs. Leaves linear, 7–15 ´ 0.5–2 mm, alternate; stipules absent; margins sometimes scabrid from a few hairs, apex usually with one such hair.
Flowers solitary, axillary. Pedicels 7–14 mm. Sepals markedly unequal, the three inner ones 7–9 ´ 4–6 mm, prominently veined, the two outer ones similar to the leaves but only 4–5 ´ 0.2–1 mm. Petals 5, caducous, 5–8 ´ 4–7 mm, pale yellow. Outer stamens sterile, less than 10, moniliform (like a string of beads); inner ones fertile, less than 20. Style filiform, ± geniculate at base; stigma ± undivided, with short papillae. Capsule loculicidal, 7–8 mm, trigonous, broadly ovate in outline; valves 3, usually patent after dehiscence. Seeds 5–10, dark brown, smooth, 2–3 mm, trigonous but often slightly compressed, ovate in outline; sides convex. – Mid-summer to late summer.
Distribution. Nem–SBor. – S Öl Böda (Mensalvaret), Sandby (several localities) and Stenåsa (east of Bårbykällan); Gtl scattered in areas dominated by hard limestone.
Outside Norden in W, S and C Europe (north to C Germany), S Ukraine, the Caucasus, N Iran.
Habitat. Sunny, well-drained habitats with sparse vegetation on hard limestone usually covered with a thin layer of weathering gravel; very rarely on calcareous, shifting sand. The life length of individual plants is often limited by frost upheaval which gradually leads to uprooting. The species does not stand intensive grazing, but, at least in Öland moderate grazing seems to be necessary to keep the localities sufficiently open for the species. In Gotland, on the contrary, it has increased during the 20th century because large alvar areas are no longer grazed (Pettersson 1958).
Biology. The roots are woody with sparse fine roots and without root hairs. New shoots and seedlings grow upwards, while branches on older plants extend horizontally in right angles to the dying apical shoot (thereby the plants get a zigzag appearance when seen from above). No vegetative propagation occurs. The development of individual flowers is accompanied by characteristic movements of the pedicel. The pedicel of the young flower bud is straight, thus the bud is pointing along the shoot and is hidden among leaves. Before anthesis the pedicel bends upwards and during anthesis the petals are exposed; the petals are held horizontally at anthesis. The flowers open in the morning and are ephemeral (2–5 hours; the petals fall well before noon). They offer neither nectar nor large amounts of pollen to pollinators and the species is almost exclusively self-fertilizing. Adding extra pollen to open flowers gave marginally more seeds than bagged flowers in a field experiment (Bengtsson, unpublished). After flowering the sepals close around the stamens and the pistil and the pedicel starts bending downwards; the sepals remain around the capsule. The whole procedure of pedicel bending takes about 48 hours according to Vestergren (1909). The capsules mature in two to four weeks depending on weather conditions. The prostrate growth habit and the fact that the capsule opens downwards are likely to restrict the average distance of seed dispersal outside the immediate neighbourhood of the maternal plant. According to Vestergren (1909) and Pettersson (1958), long-distance dispersal of unopened capsules during the winter may however be possible.

3. Tuberaria (Dunal) Spach 

Spach, Ann. Sci. Nat. Bot. Ser. 2, 6: 364 (1836). – Basionym: Helianthemum sect. Tuberaria Dunal in DC., Prodr. 1: 270 (1824)..
Tuberaria guttata (L.) Fourr. 1868. F täplänouto. S fläcksolvända. – Annual with a basal leaf-rosette. Stem ± erect, 10–30 cm. Leaves distinctly 3-veined, at least the upper ones with stipules. Petals 5–8 × 4–7 mm, usually with a large blackish spot at the base. Stigma sessile. – [2n=36]
F U Helsinki (Drumsö) 1940 (with Moroccan cork), EK Kymmenlaakso (Kotka) 1988 (with timber). – Mainly Mediterranean (S and W Europe north to S England and E Germany, Turkey). – Map (not in the book).
The species is extremely variable throughout its range. The specimen from EK is average for the species, with narrowly elliptical leaves and with bristles as well as stellate hairs all over, while the specimen from U has an extremely lax inflorescence, almost linear leaves with distinctly inrolled margin, and with only a few bristles on buds and leaves (stellate hairs almost absent).

References To top

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