Terminal Racemes Research Articles

Two New Taxa of Aeschynomene (Leguminosae : Papilionoideae) from Brazil

Summary. Aeschynomene soniae, a new species from Bahia, Brazil and A. genistoides var. latifoliola from Goias, Brazil are described and illustrated. The new Bahian species described below seems as closely related to the Mexican Aeschynomene hintonii Sandw. as to its closest Brazilian relative, A. martii Benth. The second taxon also originally seemed to be a new species, but after further study I concluded that it was separable from A. genistoides (Taub.) Rudd only by leaflet size and number. Aeschynomene soniae G. P. Lewis sp. nov. A. hintonii Sandw. speciei Mexicanae affinis sed floribus maioribus carinae petalis minus rostratis fructus articulis distincte longioribus quam latioribus differt, A. martii speciei Brasiliensi etiam affinis sed foliolis pergrandioribus atque in quoque folio perpaucis differt. Typus: Brazil, Bahia, Lewis & Andrade 2006 (holotypus CEPEC; isotypi plures). Spindly flexuous shrub to 5 m tall, main stem up to 2 cm in diameter; bark rough, brown, peeling; young stems sparsely to moderately pubescent with short, white patent hairs and a few swollen-based hairs intermixed. Stipules lanceolatetriangular, c. 1 - 5-3 mm long, persistent, striate, sparsely pubescent, the margin with occasional swollen-based hairs. Leaves imparipinnate with 3-7 alternate to subopposite bluish green leaflets; petiole up to 2 cm long, sparsely pubescent near base; petiolules 1 mm long; leaflets very variable in shape and size, narrowly ovate to broadly elliptic or orbicular, up to 3 - 4 x 3 cm, the apex rounded to obtuse, mucronulate, the base rounded, sometimes evidently asymmetric, both surfaces glabrous, the upper surface nitid, venation prominent, secondary veins brochidodromous, tertiary veins reticulate. Inflorescence an axillary or terminal raceme sometimes compounded into lax panicles; pedicels 5-7 mm long, clothed with a mixture of patent white hairs and yellow swollen-based hairs; primary bracts lanceolate, acuminate, up to 4 -5 mm long, persistent, striate, pubescent, swollen-based hairs on margin; secondary bracts lanceolate-deltoid, c. 2 mm long, otherwise as for primaries; bracteoles narrowly elliptic, acute, c. 2 -5 mm

Six New Species of Adenocalymna (Bignoniaceae) from Eastern South America

Six new species of Adenocalymna are described from Brazil and French Guiana. Adenocalymna is one of the genera of Bignoniaceae tribe Bignonieae that is most prone to local endemism (Sutherland, 1983). Six new species of the genus are included in recent collections from eastern South America. Adenocalymna dichilum A. Gentry, sp. nov. TYPE: Brazil. Piauhy: Bom Jesus-Sao Raimundo Nonato, caatinga, 11 May 1979 (fl), A. Fernandes s.n. (EAC 6185), (holotype, EAC; isotype, MO). Frutex scandens, ramulis teretibus. Folia 2(-3?)-foliolata, interdum cirrho simplici, foliolis ovatis vel ellipticis, infra valde villosis. Inflorescentia floribus in racemo terminali dispositis. Calyx cupulatus, 5-dentatus, 12-14 mm longus; corolla lutea, valde bilabiata, extus puberula. Capsula ignota. Liana; branchlets terete, longitudinally striate, with scattered small inconspicuous lenticels, finely puberulous with small suberect whitish trichomes; pseudostipules ovate, 3-4 mm long; interpetiolar glandular fields absent. Leaves 2(-3?)-foliolate, the terminal leaflet sometimes replaced by a simple tendril, the leaflets ovate to elliptic, obtuse to emarginate at apex, rounded to distinctly cordate at base, 2-4 cm long, 1.5-3.5 cm wide, above + glabrescently puberulous with short erect trichomes, below persistently villous, coriaceous, drying brownish above, olive below, the tertiary venation prominulous below, finer venation obscured by the indumentum; petiole 1.5-2.5 cm long, petiolules 0.2-0.9 cm long, rather densely tomentose with multicelled trichomes. Inflorescence a terminal raceme, densely tannish tomentose, with pair of caducous obovate coriaceous bracts ca. 1.5 cm long subtending each node, each bract with several large plate-shaped glands, the pedicels 1-1.5 cm long, with pair of ca. 1-cm-long elliptic bracteoles near apex subtending calyx. Flowers with the calyx cupular, shallowly 5-dentate, 1214 mm long, 9-10 mm wide, tannish puberulous, with conspicuous plate-shaped glands near margin; corolla yellow, ? tubular, strongly bilabiately split almost to middle, ca. 3.5 cm long, ca. 1 cm wide at mouth of tube, the tube ca. 1.8 cm to base of split, the lower lobes narrow, ca. 1 cm long, the upper two lobes with free part ca. 3 mm long but basally fused to form 1.5-cm-long upper lip, densely puberulous outside except for base of tube; stamens subexserted, the thecae subparallel, pendulous, ca. 6 mm long; pistil and disk not examined. Fruit not

Sulphur turnover in the developing pods of single and double low varieties of oilseed rape (Brassica napus L)

AbstractChanges in the sulphur (S) concentrations in pod walls and seeds of the double low variety Cobra and single low variety Bienveou of winter oilseed rape (Brassica napus L) were studied during pod development. The S concentration in the seeds of Cobra increased between 47 and 61 days after flowering and thereafter remained stable, whereas in Bienvenu seed S concentration was much higher initially and continued to increase throughout the sampling period (from 57 to 108 days after flowering). These differences in S concentration reflect different patterns of glucosinolate accumulation in the seeds. In contrast, there was a large and progressive build‐up of S in the pod walls of Cobra, such that at maturity the S concentration in the pod walls of Cobra was approximately double that of Bienvenu. A large and progressive accumulation of inorganic sulphate was found to be responsible for the build‐up of S in the pod walls of the double low variety. Short‐term feeding experiments with terminal racemes showed that a smaller proportion of 35S was translocated from the pod walls to the seeds in Cobra than in Bienvenu. However, the build‐up of S in the pod walls of Cobra did not seem to result from a restricted translocation of glucosinolates, since in both varieties exogenously supplied allylglucosinolate was translocated rapidly from the pod walls to the seeds. These results are therefore consistent with the hypothesis that pod walls are a major site for the biosynthesis of glucosinolates present in the seeds, and a metabolic block in the pathway of glucosinolate biosynthesis is responsible for the low glucosinolate concentration in the seeds of double low varieties, which consequently results in a large build‐up of sulphate in the pod walls.

New Species of Stachys (Labiatae) from Tropical Africa

Erect branching herb, 40 cm to 1 m high. Older branches pale brown, young parts pilose. Indumentum a mixture of simple, biramous and stellate trichomes. Leaves opposite, discolorous, pale green, turning dark brown on drying above, greyish-white below, pubescent on both sides; petiole 3-14 mm long, pilose; lamina ovate 2-7-3 x 1-3-4 cm, rounded, acute to acuminate at the apex, cordate at the base; margin regularly crenate-serrate. Inflorescence a simple terminal raceme, with 4-8-flowered verticillasters in the axils of leaf-like bracts; bracts becoming smaller towards the apex; bracteoles linear 4-5 mm long, pubescent, caducous; pedicel 1-2 mm long. Calyx 10-ribbed, 5-toothed, pubescent on the outside ? glabrous inside, except for some scattered hairs, 5 5-8 mm long; tube 2-5-4 mm long; teeth slightly unequal, 2-5-4 mm long. Corolla white with pink or greenish tinge; tube 5-6 mm long, two-lipped, upper lip 2 -54 5 mm long, lower lip 3-lobed, 6-8-5 mm long, pubescent on the lower lip and tube on the outside and scattered hairs inside, except in the lower ?. Stamens 4, didynamous; upper pair 2 mm long, lower pair 3 mm long including anther. Ovary 4-locular with 1 ovule in each locule; style 5 5 5 mm long (Fig. 1).

Analysis of post-flowering compensatory growth in winter oilseed rape (Brassica napus)

SUMMARYPatterns of assimilate distribution in single plants of winter oilseed rape (Brassica napus L.) cv. Mikado, following a reduction in sink capacity at flowering were investigated in two field experiments during the 1985/86 and 1986/87 growing seasons at Cockle Park Experimental Station, Northumberland. Plants demonstrated considerable compensatory growth following the removal of flowers from the terminal raceme and primary branches.Flower removal from lower branches did not significantly reduce total seed weight. Plants with a pod-bearing terminal raceme and one, two or three productive higher-order branches yielded a similar amount of seed. When seed production was confined to the terminal raceme and first four primary branches, seed yield per plant was greatly increased. Removal of flowers from the terminal raceme and uppermost branches of plants increased the number and productivity of lower-order branches but not enough to offset the overall loss in seed yield potential per plant. Indeed, when flowers were removed from higher-order racemes, the reduction in total seed weight per plant, was directly related to the degree of flower removal. The additional seed yield obtained from individual branches of modified plants in both experiments arose largely through an increase in fertile pod number and seed number per pod. Flower removal treatments did not greatly influence mean seed weight.The results clearly demonstrated that the loss of flowers from lower-order branches could be tolerated and may even be beneficial. Conversely, the removal of flowers from higher-order branches resulted in significant yield reductions. The production of lower branches should be restricted, therefore, in order to increase the superiority of the terminal raceme and uppermost branches and to increase the overall production efficiency of the crop canopy.

Ovule Development and Determination of Seed Number Per Pod in Oilseed Rape (Brassica napusL.)

Seed number per pod at maturity over the terminal raceme of single plants of oilseed rape is closely correlated to the percentage of ovules with complete embryo sacs (ovule fertility) at flower opening. Approximately one-third of the ovules did not contain an embryo sac and sterility, due to the absence of embryo sac, accounted for most of the difference between the numbers of ovules and seeds. Within the terminal raceme, both a decreased proportion of fertile ovules and a lower number of ovules per ovary in apical flowers contributed to the lower number of seeds per pod in the mature apical pods compared to the basal ones. A study of ovule development before flower opening showed that differences in the differentiation of the embryo sacs arose before the buds were 40 mm long and probably involved the stages of meiosis II and/or differentiation of the chalazal megaspore.

Two New Species of Aeschynomene (Leguminosae: Papilionoideae) from Brazil

Summary. Aeschynomene simplicifolia and A. graminoides, two new species from Goias, Brazil, are described and illustrated. A simplicifolia is the only known unifoliolate member of the genus and A. graminoides is apparently aphyllous. During a visit to the herbarium of the Royal Botanic Garden, Edinburgh in May 1990, Dr. Jim Ratter brought to my attention a bundle of unidentified South American legumes. Amongst these I found a striking unifoliolate, pyrophytic herb evidently belonging to the genus Aeschynomene and closely related to A. genistoides (Taub.) Harms, also from Goias, and to A. carvalhoi G. P. Lewis from Bahia, both currently placed in Rudd's Series Pleuronerviae. Later the same year, while visiting herbaria in Brasilia, I spent some time attempting to trace duplicate material of the collection at Edinburgh but without success. As the only other known material of this new species is without either flowers or fruits, the Edinburgh specimen represents an apparently unicate collection of material that must be selected as the type. Aeschynomene simplicifolia G. P. Lewis sp. nov., affinis A. genistoidis (Taub.) Rudd sed foliolis unifoliolatis, haud acicularibus, floribus majoribus differt. Typus: Brazil, Goids, Gifford & da Fonseca G 241 (holotypus E). Erect pyrophytic herb to c. 20 cm tall, with many shoots arising from a woody root; stems longitudinally ribbed, densely spreading-pubescent with whitish hairs, these darker near to the base and with a tendency towards becoming glandular, also a few, scattered, longer (to c. 1 mm long) patent, swollen-based glandular hairs intermixed in the pubescence. Leaves unifoliolate; stipules persistent, lanceolate to narrowly triangular or subulate, 5-9 mm long, 1-2 mm wide at the base, striate, spreading-pubescent; petiole 5-12 mm long with a swollen pulvinus at its base, broadened into a disc-shaped pulvinus at the apex, densely pubescent with swollen-based glandular hairs intermixed; leaflets elliptic to narrowly obovate, 3 3 - 4 - 5 x 1- 3- 1-8 cm, apiculate, symmetric at the base, glabrous on both faces (the blade very finely and obscurely pellucid-dotted at x 20 magnification), the venation prominently raised on both faces, the midvein central, the margin entire, thickened into a prominent marginal vein, the secondary venation tending to be ? brochidodromous on the lower % to 34 of the blade but the upper 2 to 3 secondaries and the basal one linking with the marginal vein. Inflorescence a terminal raceme, c. 4-10 cm long, 3-4-flowered; indumentum

Shoot Meristem Activity during Floral Transition in Glycine max (L.) Merr.

The soybean (Glycine max [L.] Merr.) is a quantitative short-day (SD) plant requiring two inductive cycles for floral initiation, which occurs first in the most undifferentiated meristem in an axil of a main stem leaf. Floral initiation at the main stem apex, however, requires additional SD inductive cycles. Under continuous SD the transition to flowering in the main stem apex is completed after 8 SD cycles. Differentiation and organogenesis of the first flower in the terminal raceme is apparent after 10 SD cycles. The changes in apical size and geometry, nuclear DNA, and rate of leaf initiation were followed daily during this 10-d period and compared with apices from plants kept under noninductive long days (LD). At emergence all plants had initiated three trifoliolate leaf primordia and during the vegetative stage of development maintained a plastochron of 2.0 d/leaf. The plastochron was shortened to 1.0 d/leaf in SD plants on day 7, just prior to the end of the transition. Apical size and geometry remained unchanged until after 6 SD cycles when height of the dome decreased and there was less elongation of the rib meristem. Earlier events included significantly lower amounts of nuclear DNA in cells of SD apices after 1 and 3 SD cycles. Later, the amount of nuclear DNA increased in cells of SD apices beginning after 5 SD and peaking after 6 SD before decreasing back to control levels. Shifts in increasing proportions of the population of nuclei from the 4C to 2C condition occurred after 1 SD and 3 SD. As in other species, both of these shifts are apparently essential components for the floral transition at the shoot apex in soybean. The first shift, or "mitotic" stimulus, signals that the process of the floral transition has begun, while the second shift, or "floral" stimulus, is required for completion of the process.

Changes in Soybean Raceme and Petiole Anatomy Induced by 6-Benzylaminopurine

Our purpose was to determine the cellular changes that occured in the rachis of terminal racemes and the petiole of the uppermost mainstem leaf following BAP treatment.

Increased Pod Set of Determinate Cultivars of Soybean, Glycine max, with 6-Benzylaminopurine

Terminal racemes on determinate soybean, Glycine max (L.) Merr., cultivars Bragg and Lee were treated with three concentrations of the cytokinin 6-benzylaminopurine (BAP) to reduce pod abscission. A 1-mM BAP treatment significantly reduced pod abscission and increased the total number of pods and seeds per raceme. The effect of BAP on reducing pod abscission was apparent within 6-10 d of initial treatment. BAP caused a more than a sixfold increase in seed set for cv Bragg and almost a fourfold increase for cv Lee racemes. The greater seed numbers resulted from increased pod set. However, BAP had no effect on the distribution of one- to four-seeded pods on racemes or the percent aborted seeds within harvestable pods. A significant change in location of set pods on the rachis axis was observed for the BAP treatment

REPRODUCTIVE BIOLOGY OF THE YELLOW‐FRINGED ORCHID, PLATANTHERA CILIARIS

Platanthera ciliaris is a butterfly‐pollinated, terrestrial orchid with a loose terminal raceme of 10–50 orange flowers, characterized by a long nectariferous spur. In the southeastern United States, P. ciliaris occurs in the Appalachian Mountains and Coastal Plain physiographic provinces, but rarely in the intervening Piedmont. Of 153 plants that flowered in a Mountain population in 1983, 54 (35.2%) flowered again in 1984; in a Coastal Plain population, only 51 of 306 (16.7%) flowered in both years. Experimental pollinations showed that P. ciliaris is self‐compatible but not autogamous. Nectar volume increased over the 6‐ to 7‐day life span of a flower, reaching a maximum of 4 μl and 1.0 mg of sugar (Mountains) or 6 μl and 1.2 mg of sugar (Coastal Plain). Nectar concentrations were relatively constant in flowers of all ages and averaged 23% in the Mountains and 19% in the Coastal Plain. Diurnal patterns of nectar secretion were not well‐defined, but most nectar appeared to be produced overnight. In the Mountains Papilio troilus (spicebush swallowtail) was the most frequent and effective pollinator, whereas in the Coastal Plain P. palamedes (palamedes swallowtail) was the predominant pollinator. These large butterflies were most active in the late morning (0930–1030) and early afternoon (1230–1400). Levels of pollinator service, as assessed by rates of removal and insertion of pollinia, were higher in the Mountains (0.81, 0.86) than in the Coastal Plain (0.63, 0.67). These values were reflected in higher levels of fruit‐set in Mountain (83.9% in 1983, 86.5% in 1984) than in Coastal Plain (63.8, 65.5%) populations. Combining these observations with the fact that hand pollination increased fruit‐set of Coastal Plain flowers 6.5–13.5% above open‐pollinated controls, it appears that fruit‐set in P. ciliaris is pollen‐limited.

EVIDENCE FOR POLLINATION ECOTYPES IN THE YELLOW-FRINGED ORCHID, PLATANTHERA CILIARIS.

Platanthera ciliaris is a butterfly-pollinated, terrestrial orchid with a loose terminal raceme of 10-50 orange flowers, characterized by a long nectariferous spur. In the southeastern United States, P. ciliaris occurs in the Appalachian mountains and coastal-plain physiographic provinces, but it is found rarely in the intervening Piedmont. In 1983 and 1984, detailed observations of two populations within these disjunct areas revealed that the butterfly species that serve as the primary pollinators differ sharply. In the mountains, Papilio troilus (spicebush swallowtail) was the most frequent and effective visitor, whereas in the coastal plain, P. palamedes (palamedes swallowtail) was the predominant pollinator. Proboscis lengths of P. troilus (mean = 23.3 mm) were significantly shorter than those of P. palamedes (mean = 28.7 mm). Floral characters, most notably spur length, also differed significantly between mountain (mean = 23.8 mm) and coastal-plain (mean = 25.6 mm) plants. In both 1983 and 1984, levels of pollinator service, as assessed by rates of removal and insertion of pollinia, were higher in the mountains (0.81 and 0.86) than in the coastal plain (0.63 and 0.67). In addition, fruit-set was significantly greater in mountain (83.9% in 1983, 86.5% in 1984) than in coastal-plain (63.8% in 1983, 65.5% in 1984) populations. We hypothesize that selection pressure exerted through pollinator proboscis lengths has resulted in pollination ecotypes of P. ciliaris. The short-spurred mountain plants appear to be in equilibrium with their short-tongued butterfly pollinators, receiving high levels of effective pollination and achieving high levels of fruit-set. Coastal-plain plants produce flowers with longer spurs which, nevertheless, are shorter than optimal for insuring that very long-tongued butterflies make contact with their pollinia. Thus, effective pollinator service and fruit-set are reduced. Correlation analyses in 1984 showed a positive relationship between spur length and fruit-set only in the coastal plain. The presence of long-tongued nectar thieves in the coastal plain may also contribute to lower effective pollinator service and fruit-set. Results of reciprocal-transplant studies attempting to determine the genetic basis of floral characters, including spur length, were inconclusive but suggest that differences between mountain and coastal-plain plants are not due solely to phenotypic plasticity.

Effect of harvest date and pod position on glucosinolates in oilseed rape (Brassica napus)

AbstractPod samples from four varieties of winter oilseed rape (Brassica napus L) were taken twice weekly from 26 to 3 days before harvest from upper, middle and lower third portions of the main raceme. Seeds were analysed for individual glucosinolate concentration by HPLC. Total glucosinolate content increased suddenly during the sampling period. The timing of the increase depended on variety but occurred before harvest would have been practical. Proportions of individual glucosinolates in Rafal, the only “high” glucosinolate variety examined, did not change over the sampling period. In the other varieties, the proportion of 2‐hydroxy‐but‐3‐enyl (progoitrin) increased and the proportion of 2‐hydroxy‐pent‐4‐enyl decreased as sampling progressed, so that the concentration of individual glucosinolates could not be predicted from total glucosinolate content. The ‘low’ glucosinolate varieties contained a significantly smaller concentration of progoitrin and summed aromatic glucosinolates than Rafal. Variations in glucosinolate content with pod position were smaller than those due to sampling date, but there was a greater concentration of glucosinolates in seeds from pods lower on the terminal raceme. The results would indicate that care should be taken if seed samples from the plant are taken.

Glucosinolates in oilseed rape (Brassica napus) and the incidence of pollen beetles (Meligethes aeneus)

SummaryDuring an early stage of migration into a field of oilseed rape in the spring of 1988, more pollen beetles were observed on the double‐low variety, Ariana, than on the adjacent single‐low varieties, Bienvenu and Mikado. More beetles were found on open flowers on terminal racemes than on yellow and green flower buds on lateral racemes.Five alkenyl, three indolyl and two aromatic glucosinolates were identified in the floral tissues of oilseed rape. The major compounds were progoitrin (2‐OH, 3‐butenyl) and glucobrassicanapin (4‐pentenyl). There were no differences in the types and concentrations of glucosinolates present in the terminal and lateral racemes of any variety, and only small differences between single‐ and double‐low varieties. Concentrations of glucosinolates in floral tissues of crops grown with a little nitrogen were twice those of well‐fertilised crops. There was no association between the number and distribution of pollen beetles on plants and the amounts or types of glucosinolates present in floral tissues.

‘UConn White’: A White-flowered Torenia fournieri

Abstract Torenia fournieri L., commonly known as the wishbone flower, bluewings, or torenia, is a bedding plant from the Scrophulariaceae. Native to Indochina, torenia plants grow well in full sun or partial shade but prefer cool, moist, shaded areas. Torenia are oppositely branched, round in habit, and attain a height of 30 cm. These low-growing annuals are attractive in garden borders but are also well-adapted to pot culture and hanging baskets. Torenia flowers are located on terminal racemes and consist of a five-winged tubular calyx. The common name, wishbone flower, refers to the shape and position of the stamens, which arch together, fusing at the anthers to resemble a chicken wishbone.

Inheritance of a Long Terminal Raceme in Soybean

A long terminal raceme of soybean [Glycine max (L.) Merr.], identified in an F5 breeding line, could be useful in studying reproductive abscission levels and in modifying plant architecture. Information on the genetic control of the trait is unknown. Such information would provide new knowledge on the genetics of soybean morphology, and would provide an estimate of the population size needed for selection purposes. The objective of this study was to determine the inheritance of long terminal racemes in soybean. Crosses were made between two breeding lines with long terminal racemes and two commercial cultivars with short terminal racemes. Some F1 plants were grown in a glasshouse to produce F2 populations. Additional F1 plants, parents, and F2 and F3 populations were field grown. Measurements of terminal raceme length and floret number were made on field‐grown plants at the R6 developmental stage. A continuous distribution for terminal raceme length in both the F2 and F3 populationsuggests that the trait is quantitatively controlled, but some dominance for short terminal racemes seemed to be evident. Regression of the mean F3 floret number on F2 terminal raceme length provided an estimate of an increase of 1.8 florets in F3 lines for each 1‐cm increase in terminal raceme length of their F2 parent. Thus, selection for terminal raceme length may be used to indirectly select for floret number per raceme. The standard unit heritability estimate for selection of terminal raceme length on F2 plants was 61%. Only 3% of the F3 lines had a mean terminal raceme length within the range of the donor parent, indicating the need for large segregating populations for recovery of the trait.

The Identity of Tephrosia heterophylla Vatke (Leguminosae)

Summary. Tephrosia heterophylla Vatke is considered to be an earlier name for the species currently called T. schweinfurthii Defl. in southern Arabia and northeast tropical Africa. Synonymy, typification and a distribution map are given. Tephrosia heterophylla Vatke (1878) was described on the basis of the collection Hildebrandt 835a from 'Mt Ahl' (today's Al Mts) in northern Somalia. According to the description it is a plant with usually simple leaves and lax-flowered terminal pedunculate racemes, but the type is most probably no longer extant. Lanjouw & Stafleu (1957) state that the material from Hildebrandt's journey in 1872-74 was distributed to the herbaria in B (orig.), BM, BR, CORD, GOET, K, KIEL, L, LY, MO, P and W (abbreviations according to Holmgren, Keuken & Schofield 1981). In all these herbaria the type of T. heterophylla has been sought in vain either by me personally or at my request. In W, where the types of the species described by Vatke in this publication are normally found, the collection Hildebrandt 835 from Lasgori in northern Somalia is erroneously marked as the type of T. heterophylla. Vatke himself (1878: 214) correctly cited this collection as T. apollinea (Del.) DC. Since its original publication the name T. heterophylla has been used by four authors, but it is doubtful whether any of them saw the original material. Engler (1904: 383) reported the species from the area of Ganale River in Ethiopia apparently on the basis of an Ellenbeck collection in B which was destroyed during the war. Baker (1929: 183) only cited the type and added no further information. Schwartz (1939: 106) cited von Wissmann 1048 and 1668 from Yemen, collections which were housed in HBG before the war, but whose whereabouts thereafter are unknown. Finally, Cufodontis (1955: 281) reported T. heterophylla from Ethiopia apparently only on the basis of Engler's earlier record. No original material, or other specimens seen by previous authors using the name, is thus now available. A clue to the identity of Vatke's name was found at BM, where there is a sketchy drawing of T. heterophylla made before the war by E. G. Baker. It illustrates an Ellenbeck collection borrowed from B which was most probably the basis for Engler's earlier record (Thulin 1983: 74). This drawing matches exactly the species currently called T. schweinfurthii Deflers (1895) which occurs in NE tropical Africa and Arabia and furthermore is known from the Al Mts in Somalia. This species also, in most respects, agrees well with the original description of T. heterophylla, but there are two somewhat doubtful points. Vatke's description of the leaves and inflorescences of T. heterophylla reads respectively: 'foliis plerisque simplicibus, nunc binis conjugatis' and 'racemis

Photoperiod Regulation of Vegetative Growth and Meristem Behavior Toward Flower Initiation of an Indeterminate Soybean

Soybeans were subjected to three photoperiod treatments: (1) short days-(SD) 9-h solar radiation; (2) long days-(LD) 9-h solar radiation with a 3-h night interruption; and (3) 10 short days plus long days (SD + LD). Short inductive photoperiods of SD and SD + LD promoted a rapid transition of axillary and terminal shoot meristems to the reproductive condition. Terminal shoot meristems were transformed to floral racemes, and vegetative structure differentiation stopped, coincident with the beginning of branch elongation, indicating a release from apical dominance. Long photoperiods of SD + LD and LD promoted elongation of internodes and leaf expansion. Unlike SD plants, SD + LD plants developed all of the differentiated but not elongated apical internodes, and terminal racemes became visible. In the noninduced LD plants, internode elongation was promoted, and vegetative growth of terminal shoot meristems was prolonged. The latter effect may be caused by (1) a delay in flower induction and (2) independent behavior of terminal meristems with respect to the reproductive condition of the axillary meristems. Photoperiod may regulate endogenous hormonal levels, and correlative controls of the vegetative growth are postulated.

Vegetative Activity of the Main Stem Terminal Bud Under Photoperiod and Flower Removal Treatments in Soybean

Effects of photoperiod and flower removal on vegetative activity of the main stem apical bud were examined for an indeterminate ('Williams') and a determinate ('Bragg') soybean cultivar. Plants grew under long day conditions until the V2 stage. Then, they were subjected to three photoperiodic treatments: (1) short days of 9 h of solar radiation during all the experiment (SD); (2) 10 short days followed by long days until the end of the experiment (SD + LD); and (3) long days during all the experiment (LD). From the moment anthesis was reached, half of the plants of each photoperiodic treatment were periodically deflowered. Flower removal induced an additional but limited vegetative growth of the main stem apex, due to the elongation of the youngest internodes. This effect was only seen under SD because long day applications (SD+LD and LD) induced a high flower abortion. On the contrary, long days stimulated internode elongation, leaf expansion and, under LD, delayed anthesis which resulted in enhanced vegetative activity of apical buds and a greater production of nodes and branches. Thus, a close but inverse relation was observed between flower induction and vegetative structure differentiation by apical buds. As in Bragg, Williams may stop vegetative activity of buds by their simple transition to a terminal raceme hence, only posterior differentiated internode elongation will be either limited or stimulated depending on SD or LD conditions, respectively.

Comparison of pods of the terminal raceme of rapeseed (Brassica campestris var. Yellow Sarson) and mustard (Brassica juncea) cultivars

Rapeseed and mustard cultivars aro morphologically determinate but the growth of the raceme, which is a corymbose type, is indeterminate. On the raceme flower opening proceeds acropetally in a sequential manner with one or two flowers opening each day. Thus there is a considerable time lag between first and last flower opening within the same raceme. In these oil-seed crops, besides leaves both pod wall and stems are photosynthetically active and the share of assimilates contributed by these three organs to the growing seeds has been estimated to be 37, 32 and 31%, respectively (Brar & Thies, 1977). A rapid decline in leaf area during pod filling in rapeseed and mustard (Chauhan & Bhargava, 1984) and rape (Allen & Morgan, 1972) cultivars has been observed. The assimilate supply to the pods developing at different periods may, therefore, differ owing to a decline in the leaf source as well as increasing intornal competition between pods. In winter oil-seed rape (Brassica napus), both mutual competition for assimilates and shading resulting from excessive pod production have been reported to cause heavy seed and pod losses (Mendham, Shipway & Scott, 1981). No information is available for rapeseed and mustard cultivars on how different components of the pod, such as its weight, seed weight, number of seeds and seed oil percentage, change according to their position on the terminal raceme. This information may be useful in deciding the appropriate number of pods on a raceme for optimum yield.