Not to be semantically confused with :
Californian Buckeye (Aesculus californica),
Californian Cypress (Hesperocyparis goveniana) or
Californian Incense-cedar (Calocedrus decurrens) [trees with with similar names] nor with
Californian Honeysuckle (Lonicera involucrata),
Californian Fuchsia (Zauschneria californica) or Yellow-Eyed-Grass (Sisyrinchium californicum) [more plants with similar names].
Easily mistaken for : the orange-coloured
Yellow-juiced Poppy [aka Long-Headed Poppy] (Papaver lecoqii) but that has triangular leaflets (rather than linear and glaucous), is roughly-hairy (rather than glabrous), has short and slightly-bulging seed pods (rather than long) which is topped by a conical cap and a latex which is either yellow (or quickly turns yellow in air, before drying to a reddish colour) [rather than having a watery sap].
Some similarities to : Atlas Poppy (Papaver atlanticum) but that has yellower flowers, linear leaves with triangular teeth (rather than pinnate) and also a short seed pod topped by a flattish cap.
Easily mis-identified as : Yellow Horned-Poppy (Glaucium flavum) but that has yellow flowers and grows only near the shoreline on shingle, has a yellow latex (rather than watery) and pods which are exceptionally long (15-30cm) and curved.
It is an introduced plant from California and South-West North America which is widely planted in gardens as a summer bedding plant but it also grows wild on tips and roadsides, and perennates on walls, dunes and cliff-tops in Guernsey and in quarries and beside railways in Kent.
Like most poppies it contains toxic isoquinoline alkaloids, but as is usual, many that differ from those contained in other Poppies.
At first glance the four alkaloids below appear to have an 8-membered ring, but that is just the way they are drawn, the 8-membered ring consists of two conjoined 6-membered rings. They are, in fact, still
Isoquinolines, or more correctly
BisIsoQuinolines, albeit fused ones.
Escholtzine is the simplest, appearing to be a dimer, but is not. The rings are not bilaterally symmetric either because the bridging nitrogen atom straddles the 8-membered carbon ring diagonally.
Californidine is almost identical to Escholtzine but for the extra Methyl group on the nitrogen atom, bestowing that with a positive electrical charge, making it a Zwitterion. This molecule is still not dimeric.
Caryachine is Escholtzine with one of the terminating 1,3- Dioxolane rings being broken.
NeoCarachine-7-O-Methyl- Ether-N-MethoSalt has two ether groups, one displaced in comparison to Californidine. With a separated positive charge like Californidine, it too is a Zwitterion.
Protopine is a BenzylIsoQuinoline alkaloid found also in Opium Poppy (Papaver somniferum), the tubers of Corydalis species and in other plants belonging to the Papaveraceae family. In the centre is a 10-membered ring obviously formed by the breaking of a bond in two fused 6-membered rings. It is symmetrical.
N-MethylLauroTetanine is an
aporphine isoquinoline alkaloid found in Californian Poppy.
Sanguinarine, Chelirubine and Macarpine are toxic polycyclic quaternary
Sanguinarine is a blood-red toxin which is also found in Greater Celandine (Chelidonium majus) and the non-natives:
Bloodroot (Sanguinaria canadensis),
Mexican Prickly Poppy (Argemone mexicana) and in
Five-seeded Plume-Poppy (Macleaya cordata). Sanguinarine causes apoptosis (cell death) of human cancer cells and may prove useful in cancer treatment but is so far unapproved.
Chelirubine has been used for Centuries in traditional Chinese medication. It exhibits a blue fluorescence under UV illumination and will intercalate with DNA where it has applications in medical research: by making the intercalated DNA fluoresce red (not blue) in near-UV light it highlights the red-glowing DNA strands against a glowing blue sea. Within Californian Poppy Chelirubine also produces Macarpine and DiHydroMacarpine (the latter not show).
Compared to Chelirubine,
Macarpine has an extra ether group. Your Author does not know what colour Macarpine might possess.