The flowering tops (20-40 cm) of R. oflicinalis L. were collected in April 1997 from wild plants in two different stations: Station 1 (upper gravine): This site includes calcareous subvertical walls and small areas with scanty substrate, at 250 m on the sea level, facing East. Because the site conformation and the heavy insulation, the microclimate is characterized by a high aridity. The vegetation is constituted by arboreous and shrubby species (Pinus halepensis Miller, Ceratonia siliqua L., Pistacia terebinthus L., Pistacia bntiscus L., Cistus monspeliensis L.) that are present either as isolated individuals or small groups, and by suffmticans species (Prusiuni niujus L., Saturqju niontana L., Thynius surpillum L., Thymus vulgaris L., Rosniurinus oflicinalis L.) that originate a garigue in some tracts. Station 2 (gravine): This station is constituted by the first elevations of the calcareous walls, at the bottom of the gravine, with a relatively deeper substrate with respect to station 1. The altitude is about 150 m above the sea level, facing East; all these factors and the presence of the near stream that flows on the bottom of the gravine, permit that the microclimate is more mesophile and that the aridity conditions are, as a result, less intense. The vegetation is characterized by large populations of Pinus halepensis Miller, that contribute to make the site more shady; in the undergrowth are present mainly Pistacia lentiscus L., Rosmarinus officinalis L. and Cyclanien hederifolium Aiton.

Some significant differences were observed in the qualitative and quantitative compositions, mainly for alpha-pinene (8.9-15.4%), camphor (1.4-14.7%) and borneol (2.0-6.8%). The 1,8-cineole content remained stable at 53.7-58.6%.

Rarmatinus oflcinalts was collected in the Bibans region and identified according to the Flora of Algeria. Four replicates of plants were harvested at full budding (October 1993), at the beginning of the flowering (December 1993), during full flowering (February 1994) and after flowering (May 1994).

The oil composition was observed to vary with the collection period. At all the stages of the life cycle, 1,8-cineole was the main component but with varying amounts. At full budding and at the beginning of flowering, it reached a maximum of 39.6% and 41.7% of the oil, respectively. It decreased to around 20% at full flowering and after flowering. In contrast, the camphor content reached 26% at full budding, decreased to 9.3% at the beginning of flowering, then remained constant at about 11% for the rest of the life cycle. For the other oil constituents, their contents varied randomly with the plant life cycle. The monoterpene hydrocarbons (alpha-pinene, beta-pinene and camphene) had a maximum content (18.7%) at full flowering, but monoterpene alcohols, esters and sesquiterpene hydrocarbons did not reach their maximum until after flowering.

Samples of R. officinalis were collected in April 1998 during the full flowering period (Ro-1a), between June and July 1998 during the fruiting period (Ro-1b) and in December 1998 during the hibernation period (Ro-1c) from Cazorla, Segura y Las Villas Natural Park (province of Jaen, Spain). The plant material consisted of ca. 10 twigs per plant (with blossoming tips or not, depending of the harvesting date) from 5-10 single plants. Ro-1a (Location: Las Chozuelas, Altitude (m): 1150, Harvesting date: April 21, 1998, Phenological stage: Flowering); Ro-1b (Location: Las Chozuelas, Altitude (m): 1150, Harvesting date: June 19, 1998, Phenological stage: Fruiting); Ro-1c (Location: Las Chozuelas, Altitude (m): 1150, Harvesting date: December 30, 1998, Phenological stage: Hibernation).

The highest oil yields (161.8%) were recorded during the fruiting period (summer). In general, minimum amounts of camphor and maximum amounts of alpha-pinene were observed in winter. The concentration of 1,8-cineole was almost constant throughout the year, though other oil constituent levels varied randomly with the plant life cycle