Narcissus and Daffodil

Prevention of daffodil rash
Harmful effects of Narcissus 403
Protective clothing is an important aspect in the prevention of daffodil rash.
Experienced workers are well aware that they should minimise any contact
between daffodils and the skin. Flower picking often takes place during wet and
windy weather. Waterproof clothing is essential to prevent sap soaking through to
the skin as the bunches are collected. The majority of pickers invest in good
rubber, or even nitrile, gloves, and are aware that they must avoid any gap
between the end of the glove and the sleeve of their jacket, and elastic bands or
neoprene cuffs are utilised for this. Bulb lifting takes place in the summer months,
generally under drier conditions. The workers universally wear gloves, but need
encouragement to provide adequate protection from the sun by wearing a hat and
applying sunscreen regularly.
The rash resulting from direct contact between daffodil sap and the skin of susceptible
individuals is mainly a primary irritant dermatitis. Experienced workers,
picking up to 20 000 flowers per day, have potential contact with a large volume of
sap. The amount of sap produced varies between cultivars, and also within the
same cultivar under different conditions, as direct observations confirmed (Julian
and Bowers, 1997). More sap is produced during wet weather. Pickers commented
to the present authors that the ability of a daffodil to produce an irritant rash varies
with the variety. The highly scented, multi-flowered ‘Soleil d’Or’ and ‘Paperwhite’
Tazetta narcissi, grown almost exclusively on the Isles of Scilly, rarely cause any
problem. The trumpet varieties ‘King Alfred’ and ‘Princeps’ were mentioned
specifically by older flower farmers on the Isles of Scilly. These cultivars are not
grown in quantity at the present time, but were notorious in the past for the problems
they caused. Pickers are aware of these differences: when gathering Tazetta
narcissus they hold the flower stems facing inwards, but when picking standard
varieties they turn round the stems, to avoid sap dripping onto their clothing.
Constituents of Narcissus sap
Narcissus sap contains calcium oxalate crystals, which are polymorphic and may be
multi-faceted cubes or needle-shaped (Figure 18.5). The needle-shaped crystals
are grouped in bundles known as raphides. A study by Sakai et al. (1984), which
did not include narcissus, demonstrated an increase in irritancy in species with
long raphides. With the electron microscope, it was possible to determine the
presence of barbs and grooves in the crystal structure. Their presence was associated
with irritancy. In their absence, only crystals with a length exceeding 180 µm
produced irritation in Sakai’s study. The relationship between crystal appearance
and sap viscosity to irritancy in a number of narcissus cultivars is the subject of a
current study by the present authors.
In narcissus the calcium oxalate crystals are contained within ‘slime vessels’.
These are formed by the elongation of normal parenchymatous cells and the subsequent
breakdown of their dividing cell walls. As well as calcium oxalate crystals,
they contain mucilage and alkaloids. When the flower stalk is twisted off during
picking, the slime vessel is ruptured and its contents extruded by the force of
turgidity of the adjacent intact cells (J.J. Beijer, personal communication). In this
way, calcium oxalate crystals are able to penetrate intact skin (van der Werff, 1959).