Ceylon as the station of the two species seen by him, but I am informed by Colonel Walker, who communicated the specimens, that that is an error, as he got them both in the neighbourhood of Colombo.
XANTHOPHYLLUM. (Roxb.)
1. X. angustifolium. (R. W.) Leaves narrow lanceolate, obtuse, glabrous, longer than the axillary and terminal racemes : ovary l-celled, 4-ovuled, two ascending from the base, and two pendulous from the apix of the cell : Fruit.
Courlallum in thickets. The leaves of this species which are hard and coriacious do not turn yellow in drying but are of a pale brownish colour.
2. X. undulatum. (R. W.) Leaves elliptic, oblong, acuminated, undulated on the margin, coriacious : Ovary l-celled, 4-ovuled, ovules transverse.
Courtallum. This species agrees so much in the texture and colour of the leaves as well as in the character of the ovary, with the preceding that I rather doubt the propriety of separating them, but the undulated margin, the long pointed acumen, and the much larger size, in all its parts, of the one than the other, fully warrant me, 1 think in doing so.
3. X. Roxburgianum. (R. W.) Leaves broadly elliptical, acuminated : racemes axillary and terminal, shorter than the leaves, subsecund : Ovary l-celled, 4-ovuled, two ascending, and two pendulous; Fruit.
Courlallum and Shevagerry hills in woods and thickets.
This species which differs very widely from the preceding in appearance, seems, judging from the specimens alone, to be a diffuse or scandent shrub. The leaves retain their green colour in drying.
4. X. Arnottianum. (R. W.) leaves elliptic oblong, with a short blunt acumination : under side with two pores at the base : racemes axillary and terminal : Ovules 8 — 12; attached by pairs to two lateral placenta? : fruit globose, one seeded. X. flavescens W. and A. Prod, not Roxburgh.
Woods about Courtallum and elsewhere.
5. X. flavescens? Roxb. Leaves elliptic oblong, with a longish fine pointed acumination ; numerous dores scattered over the under surface : racemes axillary and terminal, shorter than the leaves : Ovules 4, erect, attached near the base of the ovary. Ceylon—Communicated by Colonel Walker.
This is a handsome species, and is perhaps distinct from Roxburgh's flavescens though corresponding with it, in (he character of the ovary and ovules; but while unacquainted with the original species, I feel averse to add to the difficulties of a sufficiently difficult genus, by adding doubtful species. The pores on the under surface of the leaves are peculiar, from the circumstance of their being scattered all over them and not as usual confined to the base.
EXPLANATION OF PLATES 22 and 23.
22.— POLYGALA.
A. I. P. Wallichiana—natural size. 2. Flower opened, showing the calyx and corolla. 3. The same, the corolla drawn back to shew the stamens, ovary and style. 4. A stamen. 5. Style and stigma. 6. Capsule. 7. The same split vertically, showing the seeds in situ. 8. Seed. 9. Embryo. 10. Seed of Poly gala Heyneana, showing the pendulous lobes of the carunculus. 11, 12. Back and front views of P. Javana, showing the two large lobes of its carunculus — all more or less magnified.
B. 1. Salomonia obovata—natural size. 2. Calyx and corolla. 3. The same, the petals and stamens separated, showing the ovary, style and stigma. 4. Capsule- 5. The same opened, showing the seed. 6. A seed — all more or less magnified.
C. 1. Salomonia cordata—natural size. 2. A leaf magnified. 3. Flower opened, and the petals and stamens removed to show the ovary, style and stigma. 4. Capsule. 5. Capsule opened. 6. Seed. 7. The same cut transversely. 8. Embryo removed-all more or less magnified.
23.— XANTHOPHYLLUM.
I. X. angustifolium—natural size. 2. Flower. 3. Petals removed, showing the stamens. 4. Stamen separated. 5. Ovary. 6. Ovary opened, showing the position of the ovules—all more or less magnified. 7. Young fruit—natural size. 8. The same opened showing that all the ovules but one have aborted magnified. 9. Ovary of X. Arnottianum laid open, showing one placenta with its attached ovules. 10. Ovary of X. flavescens ? showing the four erect ovules— both, magnified.
XIX.-TAMARISCINEAE.
This is a small order, composed of very ramous shrubs, or small trees ; with ex-stipulate, scattered, simple, entire, sessile, minute leaves ; sometimes, in Tamarix, scale-like, closely embracing the stem, and lapping over each other, like tiles (imbricating.) The flowers are regular, hermaphrodite, generally ranged in terminal racemes or spikes; pedicels furnished with a small bractea.
The calyx is free or slightly adherent at the base, persistent, of 5 sepals, imbricated in oestivation. The torus is either obsolete, or expanded into a small disk, glanduliferous on the margin. The petals equal the number of the sepals, and are alternate with them, inferior, sometimes adherent at the base, and marcescent, or withering without falling off. The stamens are hypogynous, equalling, or double, the number of the petals, rarely, by abortion, fewer than in this proportion, (this I have observed in Trichaurus ericoides,) occasionally monadelphous at the base; the anthers 2-celled, opening longitudinally. The ovary is sessile, l-celled, usually
