Cestrum microcalyx       0

This is a shrub or tree to 6m tall, much branched from 1.5mm above the base, 5-15cm in diameter at breast height. The branches are bright grayish green, young branches puberulent. The pubescence is scant, of reduced, simple, mostly gland-tipped hairs.

The leaves are narrowly elliptical, 8-17 x 2-5.5cm, apically acuminate, the tips sometimes arching, basally obtuse, or acute, sometimes slightly oblique, margin mostly plane, firmly membranous, dark green and lustrous above, lighter beneath, glabrous, 6-11 veins on each side, often ill-spaced, ascending, major veins not impressed, elevated beneath, minor venation inconspicuous on both sides. The petioles are 7-12mm long. The minor leaves are generally wanting.

The inflorescences are axillary, short, lax, few-flowered racemes, axes 2-12mm long. The flowers nocturnal, 18-23mm long, sessile, inserted along the rachis leaving a cicatrice when fallen. The bracteoles are to 1mm long, filiform, caduceus. The calyx is tubular-urceolate, 2-3mm long, inconspicuously costate, tube 1.5-2.5mm long, glabrous, the teeth 0.5mm long, unequal, narrowly triangular, curving outward, mostly glabrate, ciliate. The corolla is light yellowish green, 19-22mm long, cylindrical, the tube slender, slightly contracted at the ovary, then hardly expanded upward, expanded apically around the anthers and contracted at the mouth. The mouth is 1.5-2mm across, the lobes narrowly triangular, 3-4.5mm long, ciliate and puberulent on the folds, otherwise glabrous. The stamens are 15.5-17.5mm long, filaments adnate for 12-15mm, pilose 1-2mm below the insertion, insertion straight, smooth, free part 2-3.5mm, anthers orbicular, 0.5mm across. The ovary is globose, 0.5-0.8mm across, disk inconspicuous, 7-8 ovules, style 16-17mm long, laxly puberulent near the apex, exceeding the stamens by 0.5mm.

The fruit is dark purple, globose, 4-10mm across, with little pulp or juice. The seeds are black, 2-3,9mm long.

- The genera Cestrum and Sessea (Solanaceae: Cestreae) in Venezuela, de Rojas, Carmen Benitez and D'Arcy, William G. Annals of the Missouri Botanical Garden 1998 pag. 273-351. JStor

- Biosystematic studies of some Egyptian species of Cestrum (Solanaceae), Eldemerdash, Marwa and El-Sayed, Ashraf and Georg, Nelly and Abou El-Nour, Amira and Nosier, Hala. Molecular Biology Reports 2021 Vol. 48. DOI
- The genera Cestrum and Sessea (Solanaceae: Cestreae) in Venezuela, de Rojas, Carmen Benitez and D'Arcy, William G. Annals of the Missouri Botanical Garden 1998 pag. 273-351. JStor

Biological type: shrub
Frost resistance: 23ºF
Leaf color: dark green
Flower color: white
Reproduction mode: hermaphrodite plant whoes flowers produce both male and female gametes
IUCN Red List of threatened species status: Least Concern

Specifications for the Mediterranean basin
Adult size (h x w): 16,4ft x 6,5ft
Sun exposure: big part shadow (Sun hours: <2h
Foliage: evergreen
Growth: fast
Flowering time from June until August

Specific information for our garden
Planting substrate: 30%Compost+30%Coco+40%Sand
Plant watering: 3x a week pH 6.5
Logical sequence of containers for: Trees; forestry plate, forestry pot 3L, container 6L, container 55L, container 110L, container 240L
Propagation is done by cuttings

SPRING Soak in acetone with 0.1% Gibberellic acid GA3, just covering the seeds, for 24:00 hours then wash thoroughly in running tap water. Sow the seeds at 5mm depth in the Well Drained Seed Sowing Mix between 68-77°F. During germination keep the substrate moist and in daylight. The seeds germinate in 3-6 weeks.
The average seed weight is 142,1 per gram (0,007037g).