An evergreen or partly deciduous shrub or small tree 5 to 30 ft high, with very downy twigs. Leaves alternate, mostly borne on short spurs, 2 to 4 in. long and 11⁄2 to 3 in. wide on plants cultivated in Britain but smaller on wild ones, roundish to elliptic-ovate in general outline, with one or three main veins springing from the base and usually with three rather shallow, blunt lobes, but sometimes almost entire, upper surface dull green, specked with star-shaped hairs when young, lower surface felted with similar but pale brown hairs; leaf-stalk generally shorter than, occasionally about as long as blades. Flowers solitary, short-stalked, borne on leafy spurs; calyx golden yellow, widely cup-shaped at first, becoming almost flat; lobes roundish, densely downy outside, each with a pit on the inside at the base which is usually hairy with long white cottony hairs, though sometimes only slightly so. Capsules ovoid, 1 to 11⁄2 in. long, acute at the apex. Seeds dull dark brown, downy, each with a conspicuous protuberance (caruncle) at one end. Bot Mag., t. 5591.
Native of California, found on the lower western slopes of the Sierra Nevada from Shasta Co. southward and in various parts of the coastal ranges; also in Arizona. It was discovered in 1846 and introduced soon after to the garden of the Horticultural Society at Chiswick, where it flowered in 1854. About five years later this plant was sold to Henderson’s nursery for the sum of £40 but died shortly after the move. In the meantime William Lobb, collecting for Messrs Veitch, had reintroduced it (1853) and since then it has been continually in cultivation.
It is not hardy in the open at Kew but has been grown successfully in a bay on the Temperate House Terrace. It is not long-lived, and although plants occasionally survive twenty or twenty-five years, growing and flowering admirably to the very last season, they are always liable to sudden collapse and death, possibly as a result of excessive wet. This species needs a light, well-drained, poorish soil and it might well be that a dressing of sulphate of potash soon after midsummer might help to keep it hard, especially if the summer is excessively rainy. Usually the plant is given a place on a wall, but this should not be necessary in the mildest parts. It flowers from May to July.
This fremontia produces plenty of its black seeds, which furnish the best and simplest means of increase. So averse is it to root disturbance that young plants should be grown in pots until planted in their permanent places.
F. (californicum × mexicanum) ‘California Glory’. – A very vigorous and free-flowering hybrid, raised from seed (sown 1952) of a fine but anomalous form of F. californicum that grew in the company of F. mexicanum on the old site of the Rancho Santa Ana Botanic Garden in Orange Co., California. The leaves resemble those of F. californicum but are five-veined from the base. Flowers shallowly cup-shaped, 13⁄4 to 21⁄2 in. across, lemon-yellow, becoming slightly red on the outside as they age; nectar-pits downy, as in F. mexicanum but with a few of the long hairs characteristic of the nectar-pits of F. californicum. Seeds black. For this information we are indebted to the original description by Percy Everett in Lasca Leaves, Vol. 12 (Jan. 1962), pp. 2-4. According to Mr Everett vegetative propagation of the fremontias is not easy but ‘California Glory’ has been increased with fair success under mist by means of tip-cuttings taken late-May to July with a slightly hardened base.
F. napense (Eastw.) R. Lloyd Fremontia napensis Eastw.; Fremontodendron californicum subsp. napense (Eastw.) Munz – This minor species or subspecies occurs in Napa and Lake Counties, California. It is described as having slender twigs; leaves 3⁄8 to 1 in. long, 1⁄4 to 5⁄8 in. wide, entire to three- or five-lobed, dull almost glabrous above, covered beneath with white down ageing to rust-coloured. Flowers 11⁄4 to 13⁄8 in. wide, yellow sometimes tinged with rose. It is perhaps not yet in cultivation but is said to be attractive (Calif. Hort. Soc. Journ., Vol. 10, pp. 143-144). For other minor species (or subspecies) of F. californicum see the monograph by M. A. Harvey cited above. A species described more recently is F. decumbens R. Lloyd (syn. F. californicum subsp. decumbens (Lloyd) Munz), a decumbent shrub up to 4 ft high and considerably more in spread, with pale orange or brownish flowers 11⁄8 to 13⁄8 in. wide. It is restricted to a few localities in Eldorado Co.