Gustavia

LecythidaceaeLecythidaceae

FIG 11. Floral characteristics of Gustavia, Grias, Cariniana, and AUantoma A-E, Gustavia hexa-petala (Prance 23413); A, Flower viewed in longitudinal section, the petals have been removed. xO.7; B, Flower with petals removed, note the symmetrical androecium. x0.7; C, Longitudinal section of 1/2 of the ovary showing the expanded placenta on the upper part of the septum. x0.96;

margin of the ring in several concentric series with the stamens of each series becoming progressively shorter from the outside to the inside of the flower. Among species, stamen number ranges from 500 to 1200. Although some species of other genera (e g Lecythis poiteaui with 1000 stamens) have this many stamens, species of no other genus of neotropical Lecythidaceae have such consistently high stamen numbers. The connective consists of a narrow constriction at the apex of the filament and bears the linear, apically dehiscent anthers (Fig 11D).

Various features of the calyx are useful for the delimitation of species. The calyces of some species (e g G. superba and G. augusta) are rim-like with only slight lobes, others (e g G. romeroi) have distinct apically rounded lobes, and others (e g G. pulchra) have distinct apically pointed lobes. Species of Gustavia section Hexapetala, G. pubescens, and G. pulchra have six lobes and all other species with lobed calyces have four lobes. The lobes of species of Gustavia section Hexapetala have inverted "Y-shaped" thickenings on the adaxial surfaces (Fig 43).

There appear to be no significant interspecific differences in petal morphology. However, the number of petals is of some taxonomic use. Species of section Hexapetala have 6 petals, whereas most other species usually have 8 or infrequently 6. Gustavia romeroi has 12 or 18 petals, a condition probably derived from an ancestor with flowers with 6 petals.

The style of species of Gustavia is always so short that it appears to be lacking. Placentation is an important diagnostic generic feature of Gustavia. The ovules are confined to the upper 112 of the locule, and the axile placenta is expanded (Fig 11C).

Grias Figs 9, 11F-L)

The actinomorphic flowers of Grias superficially resemble those of Gustavia. However, Grias flowers differ from those of Gustavia by having 4

D, Enlarged view of an anther showing the apical dehiscence characteristic of Gustavia. x 5.0; E, Cross section of the ovary showing the 6 locules characteristic of Gustavia section Hexapetala, species of other sections usually have 4 or 8 locules. x 1.6; F-J, Grias cauliflora (Nee & Mori 3663); K, Grias neuberthii (Gentry 9756); L, Grias peruviana (Wurdack 2289). F, Longitudinal section of the flower with two of the four petals removed, x 0.96; G, Longitudinal section of 1/2 of the ovary showing the pendulous ovule attached toward the apex of the septum. X 1.9; H, Cross section of the ovary showing the 4-locules and few ovules characteristic of Grias. x 2.48; I, Close-up of the anther showing how the anther sacs are separated by the filament, x 6.25; J, Bud development of Grias cauliflora showing first a young bud with the calyx forming an apical pore, then an older bud with the corolla emerging, and finally a flower after the petals and androecium have fallen. x0.96; K, Bud of G. neuberthii showing the two bracteoles directly under the hypanthium and the presence of 4 well developed calyx lobes, x 0.64; L, Bud development of Grias peruviana showing first a young bud completely enclosed by the calyx, then an older bud with the calyptrate calyx beginning to open, and finally a bud after the top of the calyx has fallen, x 0.4; M-O, Carini-ana domestica (Prance 8834); P-R, C. pauciramosa (Prance 17516); M, Lateral view of the flower with 2 petals removed, x 3.8; N, Longitudinal section of the flower, x 3.8; O, Cross section of the ovary, x 6.25; P, Lateral view of the flower with all petals removed. X4.7; Q, Longitudinal section of the flower with all petals removed. x4.7; R, Close-up of a stamen, x 15.0; S-U, AHantoma lineata (Prance 17549); S, Lateral view of the flower with all the petals removed, x 1.28; T, Longitudinal section of the flower with the petals intact, x 1.28; U, Cross section of the ovary, x 3.12.

instead of usually 6 or 8 petals, less than 215 stamens instead of 500 to 1200, anthers less than 1 mm instead of greater than 2 mm long, anthers dehiscing by longitudinal slits instead of pores, 2-4 ovules/locule instead of 7-93, ovules pendent from a non-expanded placenta instead of more or less horizontal from an expanded placenta. Moreover, the staminal ring and filaments of Grias are always more fleshy and the filaments more angular than those of Gustavia.

Calyx features provide excellent diagnostic characters in Grias. One species, G. neuberthii, has a 4-lobed calyx, the lobes of which are distinct in bud (Fig 11K). The remaining species have rim-like calyces which: 1) completely enclose the bud and open either by irregular splitting or by circum-scissile dehiscence (G. haughtii, G. colombiana, G. peruviana) or 2) enclose the bud except for a small apical pore (G. cauliflora). The only other genus of Lecythidaceae to possess all these calyx types is Barringtonia of the Old World subfamily Planchonioideae (Payens, 1967).

The petals offer no valuable diagnostic features in Grias; they are always 4 in number and fleshy. They do differ somewhat in size and thickness; G. neuberthii has the largest, thickest petals and G. cauliflora the smallest, thinnest ones.

The reduced number of ovules (2-4) per locule, which are pendent from the apex of the non-expanded septa, distinguishes this genus from all other genera of New World Lecythidaceae.

Allantoma (Figs 9, 11S-U)

Allantoma lineata, the only species of the genus, has actinomorphic flowers. The staminal ring forms a tube which bears the stamens at different levels on its inner surface. The stamens are characteristically curved downwards (Fig 1 IT).

There are five shallowly triangular calyx lobes and five narrowly oblong petals. This is the only genus of neotropical Lecythidaceae to have 5-merous flowers and oblong buds instead of globose ones. The ovules are oriented horizontally or slightly angled upwards on the lower 1/2 of the septum. The ovary is commonly 4-locular, but flowers with 5-locular ovaries are frequent in the same individual with 4-locular ones.

Cariniana (Figs 9, I1M-R)

Cariniana has a slightly zygomorphic androecium in which the staminal ring is only slightly prolonged on one side and which does not have a well defined hood (Figs 11N, P, Q). We have included Cariniana in both major divisions of our key (i e actinomorphic vs zygomorphic) because, especially when dried, the flowers are often thought to be actinomorphic. The stamens arise from only the upper margin of the staminal ring in some species (e g C. pauciramosa) or from both the upper margin and inner surface in other species (e g C. pyriformis, C. micrantha).

The flowers of the genus have 6 sepals, 6 petals, and 3-locular ovaries. Cariniana and Couratari are the only genera of New World Lecythidaceae with consistently 3-locular ovaries.

FIG 12. Floral characteristics of Couroupita and Lecythis. A-C, Couroupita guianensis (Mori sn): A, Longitudinal section of androecium. x0.64; B, Longitudinal section of 1/2 of ovary, x 1.28; C, Cross section of ovary, x 1.28. D-G, Lecythis pisonis (Nee 8955); D, Longitudinal section of androecium. xO.96; E, Fertile stamen from staminal ring. X6.25; F, Longitudinal section of 1/2 of ovary. x2.48; G, Cross section of ovary, x 1.28. H-L, Lecythis idatimon (LBB 14653); H, Front view of an intact flower. xO.96; I, Lateral view of flower with two petals removed. xO.96; J, Longitudinal section of flower. X0.96; K, Longitudinal section of 1/2 of ovary. X2.48; L, Cross section of ovary, x 6.25; M, Lecythis corrugata (LBB 14436), longitudinal section of androecium. xO.96; N-Q, Lecythis tuyrana, N-O (Mori & Kallunki 2067), P-Q (Mori & Kallunki 5772); N, Lateral view of flower with 3 petals removed. x0.64; O, Longitudinal section of androecium with 2 petals attached. x0.64; P, Longitudinal section of 1/2 of flower, x 1.28; Q, Cross section of ovary, xl.28.

Couroupita has markedly zygomorphic flowers. The androecium has a strap-like prolongation, which arises from one side of the staminal ring and arches over the summit of the ovary (Figs 9, 12A). All of the following genera have essentially the same type of androecium. In Couroupita, the prolongation usually consists of the ligule, a stamen-free area adjacent to the staminal ring, and the hood, a stamen-bearing region at its apex. However, C. darienensis bears stamens on both the ligule and the hood. In Couroupita, both the stamens of the staminal ring and of the hood bear anthers. Thompson's (1921) study of zygomorphy in C. guianensis revealed that the cells of the ligule and hood are much larger than those of the staminal ring. This cell gigantism is also found in the pollen as the pollen of the hood anthers is much larger than that of the staminal ring anthers.

The hoods of C. darienensis and C. subsessilis are notched at the apex. In addition, the latter species has an unusual inward fold at the apex of the hood (Fig IOC).

An important diagnostic feature of the flowers of Couroupita is the 6-locular ovary with bilamellar placentae running the length of each locule (Fig 12B, C). Some species of Lecythis also have bilamellar placentae, but in these species the placentae are restricted to the lower part of the septum, and the ovaries are 4-locular.

Lecythis (Figs 9, 12D-Q)

The androecium of Lecythis consists of a staminal ring, ligule, and hood. The hood may be:

1. flat, with the distal appendages sterile and the proximal ones fertile (e g L. pisonis (Figs 9, 12D), L. usitata, L. poiteaui);

2. flat but dorsiventrally expanded, with the hood appendages completely sterile and mostly fused together (only in L. corrugata, Figs 9,12M); and

3. expanded at the apex, with the appendages completely sterile and swept backwards but not forming a full coil (e g L. chartacea, L. ollaria, L. tuyrana{V\gs9, 12N-0).

These hood modifications will be recognized at some subgeneric level in our forthcoming treatment of Lecythis.

Diagnostic features of Lecythis include a 4-locular ovary, a truncate ovary summit, and a distinction between the ovary summit and the style. In addition, the ovules are inserted at the base of the locule or on the lower part of the septum.

Corythophora (Fig 9)

The androecium of Corythophora has a dorsiventrally expanded hood (Fig 9). In the two described species, C. alta and C. rimosa, the hood appen-

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